Landmine Blasts Keep Thailand and Cambodia Near the Brink After July Border Fighting

Hidden explosives threaten a fragile ceasefire

Ten PMN-2 antipersonnel mines recovered by Thai units between July 18 and July 20 have become central to a dispute that threatens to pull Thailand and Cambodia back into open conflict. Thailand says the devices were newly planted near the site where a July 16 explosion severed a soldier's ankle. Cambodia says the blasts involve mines left behind by decades of war.

Thai officials say at least six soldiers have been maimed by mines since July. Independent specialists who examined images and demining footage say the recovered devices appear fresh in the ground. They have not identified who planted them. Cambodian demining authorities dispute the assessment of their age, saying shade, soil conditions and seasonal flooding can preserve old explosives.

The dispute remains dangerous as of October 16, 2025, because July's mine incidents were followed by artillery exchanges and air strikes. Five days of fighting killed at least 43 people and forced well over 300,000 residents from their homes. Mediation led by Malaysia, with support from the United States and regional partners, secured a ceasefire late that month, but Thai commanders continued to report injuries from hidden devices.

Both countries belong to the Ottawa Convention, which bans antipersonnel mines. Their disagreement therefore reaches beyond the location of the border: it concerns whether someone has broken a treaty intended to protect soldiers and civilians from weapons that can remain lethal for years.

For families along the frontier, the immediate concern is more basic. A halt to shelling does not make a farm path or forest track safe when an explosive may still lie beneath it. The border is already among the most heavily mined stretches of land in Asia, and both governments have spent years clearing its hazards.

How a patrol incident became a military crisis

Thai officials place the first explosion on July 16, on Thai soil near Ubon Ratchathani province, opposite Cambodia's Preah Vihear. A unit conducting a routine patrol triggered a buried device in a contested part of the frontier. Two more explosions followed along patrol routes in the same corridor in late July.

Thailand and Cambodia then moved rapidly from accusations to military confrontation. Artillery fire and air operations broke out across forested ridge lines on July 24. Border crossings closed, ambassadors were recalled, and public campaigns on television and online hardened attitudes in both capitals.

The main events unfolded over several closely connected dates:

• July 16: A Thai patrol triggered the first reported blast near Ubon Ratchathani, leaving a soldier with a severed ankle.
• July 18 to July 20: Thai units say they found ten PMN-2 mines near the first injury site.
• July 18 to July 23: Thailand documented mine removal during a period it later highlighted through demining footage and visits for foreign diplomats and selected media.
• July 24: Artillery exchanges and air operations began, leading to five days of fighting.
• Late July: Malaysian mediation, backed by the United States and regional partners, brought a halt to major operations.

The ceasefire reduced heavy fire without ending the mine dispute. Thai commanders reported further injuries near the same paths. Cambodia argued that Thai patrols had left agreed routes and entered known hazardous ground on the Cambodian side. Thailand maintained that its personnel had been attacked with recently planted devices.

The location of each incident is part of the argument because the two governments disagree over where parts of the boundary run. A patrol route that Thailand considers its own territory may fall within land Cambodia claims, making investigations into the explosions inseparable from the wider territorial dispute.

What investigators can learn from a PMN-2 mine

The PMN-2 is a circular pressure mine developed in the Soviet Union and exported widely. Its black or green casing, made from bakelite or plastic, contains a molded explosive charge and a fuze. Foot pressure activates the mechanism, turning an ordinary step into a potentially disabling blast.

The plastic body makes detection with metal detectors difficult. Its trigger can remain sensitive for years if the device is well preserved. Thailand says it does not deploy PMN-2 mines, while Cambodia says it destroyed its stockpiles years ago.

Specialists examining the Thai images and footage pointed to several details consistent with recent placement. The casings showed little bleaching from sunlight, factory markings remained readable, and the devices lacked the cracking and staining often associated with long exposure. Roots, leaf litter and insect nests had not become established around them.

The mines also appeared to have been buried shallowly and grouped along routes used by Thai patrols. Thai officials say their condition, type and placement support the conclusion that they were recently laid.

Cambodian mine authorities offer another explanation. Shaded ground, local soil and flooding can protect an old device from visible wear. Rain or wildlife can disturb mines, and people can move or replant them. Boxes of unused mines from old caches also sometimes emerge in border economies, allowing old weapons to enter the ground much later.

A reliable investigation would therefore need more than photographs of clean casings. Investigators would need records showing who recovered and handled each device, photographs tied to precise locations, examination of blast craters and secure access to sites. Patrol logs and communications from both militaries would help connect the physical evidence to movements on the ground.

Those requirements explain why Cambodia's demining authorities have requested neutral fact finding and why Thailand is pursuing the issue through the Ottawa framework and the United Nations. The age of the mines and responsibility for their placement remain unresolved without an investigation accepted by both governments.

Thailand alleges deliberate planting, Cambodia denies it

Major General Winthai Suvaree, a spokesperson for the Thai army, has described the pattern of explosions as deliberate Cambodian action, a threat to Thai sovereignty and a breach of treaty obligations. He said Thailand had exercised restraint despite repeated violations and that the Thai army had not initiated the confrontation.

Winthai directly accused Cambodia of continuing to place mines:

Cambodia continues to covertly plant landmines,

He also warned that continued incidents could lead Thailand to invoke the right of self defense under international law to protect its personnel. That warning gives the mine allegations immediate military weight, even after the halt to major fighting.

Cambodia's Ministry of National Defence rejected the accusation and pointed to the country's record in demining. The ministry said its conduct remained consistent with its international obligations:

We have never used, produced, or deployed new landmines under any circumstances, and we strictly and fully honour our obligations under international law.

Cambodia's mine action authority has called for an impartial investigation. Its leaders argue that appearance alone cannot determine when a mine was buried, particularly in ground affected by heavy rain and protected from sunlight.

Thailand's position rests on the combination of physical condition and placement along patrol routes. Cambodia's position rests on historic contamination, the preservation of old ordnance and its account of Thai movements into hazardous territory. A shared inquiry would have to examine all of those elements together.

What the mine ban requires of both countries

The Ottawa Convention, also called the Mine Ban Treaty, prohibits the use, production, stockpiling and transfer of antipersonnel mines. It also requires countries to clear contaminated land, assist victims and cooperate through transparent reporting. Thailand and Cambodia have both reported destroying stockpiles and continuing clearance work.

Replanting a mine would violate the treaty, even if the weapon itself came from an old cache. The obligation concerns its use as well as its manufacture. That makes the circumstances of placement central to the diplomatic dispute.

The treaty has no automatic sanctions system. Countries accused of violations can face criticism at review meetings, while donors can attach conditions to funding for demining or military cooperation. Its procedures also allow a member to request clarification, seek a special meeting of states or invite a fact finding mission.

Thailand has begun raising the incidents through diplomatic channels connected to the treaty and at the United Nations. Cambodia says there is no verified evidence of new use and maintains that it continues to remove historic contamination. The argument comes as some European governments, under pressure from war, are debating the future of the mine ban.

Old maps and temple claims complicate the border

The frontier dispute draws on maps from the early 1900s, when France governed Indochina. Those maps remain central to efforts to determine where the border should run, particularly around temples and adjoining land.

In 1962, the International Court of Justice awarded the Preah Vihear temple to Cambodia while leaving adjoining plots undefined. The unresolved ground around the temple continues to affect patrols, access and competing claims of sovereignty.

Thailand prefers to handle boundary disagreements through a joint commission and other bilateral mechanisms. Its leaders cite grievances associated with earlier court outcomes and resist the court's jurisdiction because of past losses connected to Preah Vihear.

Cambodia favors outside adjudication, including involvement by the United Nations and a return to the International Court of Justice. The two governments therefore disagree about both the boundary and the institution that should settle it.

Nationalist politics make that disagreement harder to contain. Routine patrols and access to temples can become flashpoints when each government faces pressure to defend territory. Statements by some Thai military figures about retaking disputed temples have strengthened the hawkish mood, while Cambodian leaders have presented Thailand as the aggressor.

Mediation slowed the fighting, while relations deteriorated

Thailand closed several northeastern border crossings, withdrew its ambassador and expelled Cambodia's envoy during the crisis. Cambodia responded by downgrading relations and imposing trade and cultural restrictions. Each side accused the other of entering disputed ground and breaking a truce that had barely taken hold.

Malaysia, acting as chair of the Association of Southeast Asian Nations, convened talks with United States backing and support from regional partners. The ceasefire was followed by measures including direct communication between local commanders, restraints on heavy weapons and the deployment of ASEAN observers in contested areas.

Those arrangements created ways to monitor events and address incidents before they spread. They did not settle the territorial claims or the mine allegations, which continued to drive distrust after the major exchanges stopped.

The contest over public opinion also remained intense. Cambodian accounts linked to the state and accounts on social media spread aggressive claims, including false reports about downed jets and poison gas. Thai authorities issued official statements and arranged controlled media visits to mine sites, but struggled to match the pace of the online campaign.

National pride and painful history shape how much room leaders have to compromise. The same incident can become a military problem at the border and a political test in the capital, especially when dramatic claims circulate faster than investigators can establish events.

Domestic political strains narrow room for compromise

Bangkok entered the border emergency with tensions between the elected leadership and the army. A leaked conversation involving the prime minister's family further weakened trust. The premier was suspended in early July while an ethics inquiry proceeded, reducing civilian authority at the height of the crisis.

That strain complicated decisions about military action, negotiations and the public account of what had happened. Thailand's leaders had to manage the border confrontation while authority within the government was under pressure.

In Phnom Penh, former leader Hun Sen continued to hold enormous influence over the ruling party and security services. His presence in the information space underlined Cambodia's hard line and helped rally support at home.

Domestic pressure in both countries therefore affected more than speeches. It shaped the environment in which commanders and political leaders made decisions, alongside formal military orders and diplomatic agreements.

Families, workers and businesses bear the cost

More than 300,000 people evacuated homes near the forested escarpments during the July exchanges, and at least 43 people were killed. Farmers, people gathering food or materials in forests, and traders now face the added fear of explosives on paths they once considered safe.

Sergeant Tanee Paha, a Thai soldier who lost limbs in recent blasts, illustrates the lasting injuries hidden mines can cause. For victims, the consequences continue long after artillery falls silent. For nearby villagers, uncertainty about where mines lie can restrict work and movement even without another explosion.

Border closures disrupted trade that had exceeded $10 billion a year. Cambodian immigration authorities recorded waves of migrant workers returning from Thailand, including hundreds of thousands passing through Poipet in the weeks after the fighting.

The returns reduced the flow of money workers sent home. Those remittances reached $2.8 billion last year and represented a significant share of Cambodia's economy. Returning workers also added to unemployment near the frontier, while Thai businesses dependent on Cambodian labor faced higher costs and delays.

Cambodian retailers sought replacements for Thai goods that had dominated their shelves. Vietnamese suppliers filled gaps, while farmers selling across the border often faced lower prices. Vehicle and electronics imports were delayed along a corridor where goods had previously moved more easily.

Tourism suffered as visits to places including the eleventh century Preah Vihear temple declined. Damage at the temple complex also reduced earnings for small vendors dependent on pilgrims and tourists. The economic losses spread across households, markets and businesses on both sides of the boundary.

Practical steps could reduce danger without settling every claim

An independent investigation accepted by both governments could give the mine dispute a common factual basis. A team drawing on specialist mine action bodies could collect devices, map explosion sites, examine soil and weather conditions, and review patrol records.

Presenting findings through Ottawa Convention procedures would bring the evidence into a shared diplomatic forum. Agreement on how to gather and handle that evidence would be essential, particularly where access to the land is itself disputed.

Thailand and Cambodia could also reduce immediate risks by publishing updated maps of safe routes, expanding clearance near villages and patrol paths, arranging joint patrols in clearly agreed corridors, and establishing a hotline between local commanders. ASEAN observers already in place could widen their coverage. A pause in exercises involving live fire near contested areas would provide another signal of restraint.

Diplomats could seek a staged reopening of trade and travel linked to steps that can be checked. Restoring ambassadors and easing restrictions on goods and cultural content would reduce the economic strain. Clear public guidance on misinformation, issued jointly where possible, could also help contain false claims.

These measures would leave the century old boundary dispute for negotiators while addressing dangers people face now. Mine clearance can protect a village regardless of which side wins the argument over responsibility, and working communication between commanders can help stop another explosion from becoming another round of fighting.

The Bottom Line

• Thailand says at least six soldiers have been maimed by mines since July and accuses Cambodia of planting new devices.
• Thai units reported finding ten PMN-2 mines between July 18 and July 20 near the first blast site.
• Specialists examining images and footage say the mines appear recently placed; Cambodia attributes the danger to old contamination and seeks an impartial inquiry.
• Five days of fighting beginning July 24 killed at least 43 people and displaced well over 300,000 residents.
• Malaysian mediation, supported by the United States and regional partners, secured a ceasefire followed by ASEAN observation and military communication measures.
• Both countries are bound by the Ottawa Convention, and Thailand is pursuing the allegations through treaty channels and the United Nations.
• Cambodia favors international adjudication of the border dispute, while Thailand prefers bilateral mechanisms.
• Closures disrupted annual trade exceeding $10 billion, migrant earnings and tourism around Preah Vihear.
• Independent investigation, expanded demining and practical agreements on movement and trade could reduce the immediate danger.