Three children were injured in Kampong Speu province’s Baset district when an unexploded M79 grenade launcher round they were playing with exploded on Friday, officials said yesterday.

Baset district police chief Yang Sokly said yesterday that the three were looking after their cows about 3.5 kilometres from their village when the cattle strayed onto a mountainside.

Most locals generally avoid the area, Sokly said, because it is known to contain unexploded ordnance – having seen fighting after the collapse of the Khmer Rouge regime – but children were unaware.

“When they climbed up the mountain they found a bomb that they thought would not work anymore because it looked too old,” he said.

“One boy among the three kids – two were girls – took a knife to pound the bomb while the other two girls stood behind him,” Sokly continued.

“The bomb exploded, causing the boy to get seriously injured from his stomach up to his head, and the other girls were just slightly injured.”

Sokly said locals were regularly informed of the dangers posed by unexploded ordnance, and that the accident would have been averted “if they took [the bomb] to their elders”.

According to the most recent available figures from the Cambodian Mine Action and Victim Assistance Authority, there were 74 mine- and UXO-related casualties – 12 of them deaths – in the first seven months of 2015.

The numbers, the authority said, represented a 38 per cent decline from the same period last year.