Government demining bodies have reacted to a United States Embassy statement on US-made chemical weapons uncovered in Svay Rieng, accusing the embassy of distorting facts and evading responsibility for its wartime legacy.

On Thursday, the embassy accused Cambodia of attempting to politicise the presence of American tear gas bombs in Koki commune, claiming Cambodian authorities knew about the bombs “for many years” and had received training from US experts on their safe removal.

The Cambodian Mine Action and Victim Assistance Authority responded the same day, repeating claims that the bombs were only discovered in January.

The next day, however, Heng Ratana, head of the Cambodian Mine Action Centre (CMAC), released a report with eyewitnesses saying the bombs first began to spread in 2010. Despite this, Ratana also blasted America’s “insulting” statement.

“The statement is intended to insult Khmers, who died and are suffering from the chemical weapons, particularly insulting the forces who risk their lives to directly remove the chemical weapons,” Ratana wrote.

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On Saturday, Ratana wrote the barrels are also rigged with “explosive and fuses”.

Weapons expert Richard Guthrie confirmed CS bombs typically featured a “burster charge to disperse the material effectively”. While he said the demining teams should be “cautious”, he added that “the charge would be relatively small”.

Ratana also called on the Organisation for the Prohibition of Chemical Weapons (OPCW) to provide a “transparent” report.

In a telephone call yesterday, Ratana said the Ministry of Foreign Affairs had already filed an official request to the OPCW.

The issue of the bombs has become a political talking point, with numerous government officials decrying the weapons at a time of heightened tensions between the Cambodian government and the US. The US, meanwhile, currently gives $2 million per year to CMAC, with annual funding of the demining sector amounting to around $6 million.

CMAC’s report drew from 10 local eyewitnesses who saw the bombs dropped in 1970 during the Vietnam War, before burying them the following year.

In 2010 and 2011, villagers reported seeing the bombs again when school students began clearing an area of the grounds to plant a garden.

“The smell made some students tear up and feel sick . . . from that time the information of the bombs began to spread,” the report read.