The Cambodian government has sent a second diplomatic note in the space of three days to the Vietnamese embassy, demanding an end to encroachment across an as-yet-unmarked section of the shared border.

The second note – published yesterday by Foreign Affairs Minister Hor Namhong on his Facebook page – followed the discovery of three more ponds apparently dug by Vietnamese nationals deep in the jungle of Rattanakkiri province, between 315 and 425 metres into Cambodian territory.

“The Royal Government of Cambodia demands the Government of the Socialist Republic of Vietnam to respect the borderline of the map Bonne 1/100,000”, reads the note, referring to the map agreed upon between the two nations as part of a 1985 territorial treaty, and reinforced during a supplemental treaty in 2005.

Previously, the Cambodian government sent a diplomatic note on Friday after five ponds dug by Vietnamese nationals were found in Rattanakkiri’s O’Yadav district.

Those ponds were publicised after lawmakers Um Sam An, Ou Chanrith and Mao Monivann, all of the opposition Cambodian National Rescue Party, visited the area in recent weeks.

Last week, Monivann claimed he was attacked with an electric baton by Vietnamese troops who attempted to block access to the area.

Ongoing complaints from the opposition saw the ruling Cambodian People’s Party last month tell the CNRP to stop stirring up animosity with “bad propaganda” about Vietnamese border encroachment.

However, the CPP has now joined calls for Vietnam to be held to account over the alleged encroachment.

That about-face was welcomed by CNRP leader Sam Rainsy during a trip to Preah Sihanouk province over the weekend.

“We are the opposition party and we oppose this government, but if they do something good we must recognise it,” Rainsy told a crowd of hundreds of supporters.

“So we unite together to defend our territory against the Yuon,” he said, using a term for the Vietnamese considered offensive by some.

But Sam An, who in recent weeks has demanded the government supply a copy of the map they base the border on and has called for the cancellation of the 2005 treaty amendment, remained less enthused by the government’s notes.

Instead, Sam An wants the map registered with the United Nations in 1964 by late King Norodom Sihanouk to be enforced, a copy of which he plans to present to the border affairs and foreign affairs ministers.

“We will summon His Excellency Var Kimhong and Excellency Hor Namhong to clarify [the map] in the National Assembly and I will show [it to them],” Sam An said.