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A coalition of Cambodian civil society organizations launched a report revealing the alleged use of chemical weapons by the Thai military during armed clashes along the Cambodian–Thai border, calling for a complaint to be filed with the International Court of Justice to seek remedy.
Since the five-day July clashes, renewed fighting in December spread well beyond earlier flashpoints, with more than a dozen fronts active along the 817 km (508 miles) shared border. The latest attack, lasting 21 days from December 7, resulted in 31 civilian deaths and over 90 injured in Cambodia.
Findings in the report titled Border Crisis Response, Rapid Assessment Finding, and Next Action were based on a survey conducted from July to September last year. It showed that the alleged release of chemical substances by the Thai military posed “serious health risks” and significant environmental impacts from exposure to chemical weapons, especially in Preah Vihear and Oddar Meanchey provinces.
The organizations said they were concerned about the Thai military’s actions in Cambodia, particularly human rights violations, CHRAC executive director Ros Sotha said in a joint press conference on Monday. “People are seriously affected by water consumption, including rainwater,” he added.
Due to the dangerous conditions, including toxic chemicals that impact health, water supply and paddy fields, and unexploded ordnance due to the use of cluster bombs, residents dare not return to their homes, the report said.
Sotha labeled the Thai military’s use of chemical weapons as “inhumane” and a “violation of international laws”.
The report documented widespread human health and environmental impacts following border clashes, with dozens of soldiers and civilians treated for poisoning and respiratory symptoms between July 24 and September 5, 2025. Some 95 out of 499 soldiers in Preah Vihear hospital showed poisoning symptoms.
At Oddar Meanchey hospital, 253 patients were admitted (seven civilians, 237 soldiers), with 24 patients diagnosed with respiratory disease.
Up to 121 affected villages surround the clash areas, located along the Dongkrek mountain range, and many households have temporarily abandoned their homes due to the fear of being exposed to toxic smoke, the report said.
Laboratory analysis of rainwater samples from both provinces revealed critical safety violations, with pH levels (8.9–9.1) exceeding acceptable standards and aluminum concentrations reaching 0.31 mg/1—well above the 0.2 mg/l safety limit.
The data suggested potential chemical contamination, raising concern about a possible link to military munitions posing serious long-term health risks. “Rainwater is currently deemed unsafe for consumption,” read the report.
Sotha called on the government, and affected people, to come together and collect evidence to seek justice and compensation by filing a lawsuit with the ICJ.
Despite a ceasefire that came into effect on December 27, the Thai military occupied and fenced off land and houses belonging to innocent Cambodian civilians by placing shipping containers and barbed wire on Cambodian territory, following military attack.
Cambodian government spokesperson Pen Bona condemned the actions, calling them a grave violation, and accused Thai forces of looting civilian property.
“The laying of container ships and barbed wire [by the Thai military], as well as the planting of national flags in areas they illegally occupied, clearly demonstrates a violation of Cambodia’s sovereignty,” Bona said at a press briefing on Monday.
