Four types of US-made unexploded ordnance were unearthed by construction workers in Battambang town’s Chamkar Samrong commune yesterday, authorities said.

Battambang town deputy police chief In Rotha said that the ordnance were buried under a plot of land belonging to 54-year-old Chamkar Samrong resident Seng Kemsuor, who upon finding the dangerous materials handed them over to the Cambodian Mine Action Centre.

Pring Panharith, a CMAC official, said that the uncovered materials included 5 kilograms of M16 cartridges, six hand grenades, 29 M79 grenade launcher rounds and a claymore mine.

According to Panharith, the ordnance – some of which was still usable – were buried just half a metre underground. CMAC will now impound and detonate the explosives. “At first they found only two ordnance, but when we dug deeper we found more of them,” he said.

Panharith said he suspected they were left over from the civil war period before 1975, though his team had never found a similar haul.

There were 85 mine- and UXO-related casualties in the first nine months of 2015, down nearly 40 per cent from 135 during the same period last year, according to the Cambodian Mine Action and Victim Assistance Authority.