In an urgent development along the Thailand–Cambodia frontier, the Royal Thai Army has unveiled compelling evidence pointing to the deliberate emplacement of Russian-made PMN-2 anti-personnel landmines by Cambodian forces on Thai soil.

Officials report that during clearance operations on August 4 in the Phu Ma Kua area—territory previously held by Cambodian troops—Thai military engineers uncovered a significant number of concealed PMN-2 landmines, both staged and already buried. The Royal Thai Army underscores that these mines were newly placed, corroborated by the fact that similar devices had not been detected during prior clearance efforts, such as those conducted by the Thailand Mine Action Centre between 2020 and 2022 near Ta Muën Thom temple .

From July 15 to August 12, five separate incidents occurred in which only Thai soldiers were injured, sustaining wounds from freshly implanted PMN-2 mines—an impossible scenario of self-infliction, officials argue . On one occasion, a Thai soldier lost a foot while another sustained severe ankle injuries near Ta Muën Thom temple, with two more soldiers suffering lesser wounds .

The mounting evidence includes social media footage from July 30, where Cambodian influencers filmed clusters of PMN-2 mines near Ta Kwai Temple. On August 22, Thai troops pursued Cambodian soldiers clad in specialized military attire near Hill 350 and discovered three more PMN-2 mines upon inspection .

A critical piece of verification surfaced on August 19, when Thailand’s naval bomb-disposal unit retrieved a Cambodian soldier’s mobile phone. The device contained photos and video with location stamps linking Cambodian troops directly to the mined area .

Adding further gravity, Thailand invoked Cambodia’s own Ottawa Convention submission: as of December 31, 2024, Cambodia reported retaining over 3,700 anti-personnel mines—including PMN-2 models—for training under permitted treaty provisions. Meanwhile, Thailand affirms it destroyed all its PMN-2 stockpiles by 2019 and has none in inventory .

Following these developments, the Thai Ministry of Foreign Affairs has formally notified the United Nations Office in Geneva of breaches of Article 1 of the Ottawa Convention, detailing multiple injuries to Thai military personnel and seeking international intervention under the convention’s compliance mechanisms . A separate formal complaint, lodged with the UN Secretary-General, frames the actions as violations of international law including Article 2(4) of the UN Charter .

Cambodia, however, continues to emphatically deny any deployment of new landmines, insisting that its clearance efforts remain robust and its conduct fully consistent with treaty obligations. Its mine-action authority maintains that recent incidents stem from unexploded remnants of past conflicts rather than fresh provocations .

The recent spike in landmine injuries—occurring even after a ceasefire took effect on July 29 following days of armed clash—threatens regional stability. Thailand, upholding its sovereignty and commitment to treaty law, stands ready to pursue compliance through diplomatic and, if necessary, defensive channels.

Context and global significance This border dispute illuminates the broader challenge of enforcing international treaties like the Ottawa Convention. While both Thailand and Cambodia are signatories, the former’s steadfast adherence and transparent demining work contrast sharply with allegations of clandestine mine-planting. Thailand’s restrained but resolute pursuit of international accountability underscores its leadership in upholding humanitarian norms in Southeast Asia. Cambodia’s extensive national demining and its prior role as chair of an Ottawa Convention review meeting reflect regional contributions—but in light of new allegations, global scrutiny is intensifying.