Cambodia’s Ministry of National Defence said Thai military forces fired M79 and M16 weapons at the O’Smach border checkpoint on Tuesday while foreign military attachés from multiple countries conducted a pre-notified observation visit.
Five instances of gunfire occurred between 10:35 AM and 11:09 AM, the ministry stated, with nine rounds fired in total. The ministry did not report casualties or damage from the gunfire. The Military Attachés Corps in Phnom Penh, facilitated by Cambodia’s defence ministry, had begun its on-site inspection at the Oddar Meanchey checkpoint at 10:20 AM as part of the corps’ second annual tour of 2026. The first shots came 15 minutes after the delegation arrived.
Cambodia’s Military Region 4 Regional Border Committee Secretariat had issued formal notification to the Thai 2nd Army Area RBC Secretariat before the visit, according to the ministry.
The GBC Joint Statement signed on 27 December 2025 commits both countries to an immediate ceasefire involving all types of weapons and requires them to avoid unprovoked firing toward the other side’s positions or troops. The agreement states it “must not be violated under any circumstances.” A separate paragraph prohibits provocative actions that may escalate tensions.
No Thai government or military response to the incident had been located at time of publication.
The ministry called the incident “contrary to the spirit of the ceasefire and the agreements established by both sides.” Cambodian forces would continue to monitor the situation, the statement said.
The day before, the same MACPP delegation visited sites in Pursat province, where the ministry reported Thai forces had blocked the Chey Chumneas checkpoint with shipping containers and barbed wire. The delegation also visited Stung Meteuk Bridge, which Cambodia says was destroyed by a Thai airstrike on 13 December 2025.
O’Smach has been the border’s most contested point since the ceasefire took effect. Thailand deployed approximately 70 troops and armored vehicles to the checkpoint on 2 April, prompting a formal Cambodian protest. On 27 April, Thailand’s Joint Information Center organized a media visit to present Thai control over what it described as a scam compound at the site.
The MACPP first toured border areas in August 2025 with participants from nine countries. A ministry briefing to the corps listed representatives from 12 countries. The ministry did not specify which countries’ attachés were present at O’Smach on Tuesday.
Cambodia’s foreign minister Prak Sokhonn addressed the ASEAN-EU Foreign Ministers’ Meeting in Brunei on the same day, calling for respect for international law and citing border tensions with Thailand.
