Opposition lawmaker Mao Monivann has claimed he was attacked with an electric baton by a Vietnamese soldier during a recent visit to the border region of Ratanakkiri province, as he attempted to gather evidence of encroachment into Cambodian territory.

Monivann went alongside more than 100 local people to observe a number of illegally dug ponds in O’Yadav district, and says his way was blocked by Vietnamese security personnel with AK-47s, grenades, electric batons and dogs.

“They used the electric batons against me,” he said, adding that the Vietnamese labelled the area a “neutral zone” with access forbidden. Upon finally entering the area, the group reportedly encountered seven large man-made ponds, reportedly used for cashew and coffee cultivation.

Cambodians living in the area claim to have long cultivated the land, however last month they complained about the digging of ponds and closing off of access by Vietnamese officials.

The alleged encroachment comes as the opposition is demanding the government provide a map of the national boundaries it enforces. The government’s most senior official on border affairs, Var Kimhong, was unavailable for comment.