Cambodia and Vietnam will set up a joint committee to probe a brawl between an opposition party-led group and Vietnamese border authorities and villagers on Sunday, it was announced yesterday.

More than 12 people, including seven Vietnamese, were injured during the confrontation in Svay Rieng’s Kampong Ro district near border marker 203.

Some 250 activists, led by Cambodia National Rescue Party lawmakers Um Sam An and Real Camerin, were attempting to inspect a Vietnamese-built road, which they say is inside Cambodian territory, when the violence occurred.

Vietnam’s Foreign Ministry spokesman said the “extremist” group instigated the brawl. Sam An and Camerin say the Vietnamese side attacked first and beat their group with sticks.

According to a letter, released by the Ministry of Foreign Affairs on Thursday night, the countries will soon establish a committee to get to the bottom of the incident, which followed a month of rising border tensions fuelled by several CNRP “inspections” of alleged encroachments.

Responding yesterday, Um Sam An welcomed the investigation, maintaining the group was in the right.

Sam An said the probe should include input from civil society to ensure independence.

He said 12 CNRP lawmakers had written to Prime Minister Hun Sen to request that the allegations of Vietnamese encroachment, including several irrigation ponds in Ratanakkiri and a military post in Kandal, be sent to the International Court of Justice.

Cambodia’s diplomatic protests to Vietnam, he said, had failed to stop the encroachment.

“The Vietnamese just came and settled on our land about a month ago,” he said.

“The Ministry of Foreign Affairs asked them to stop their activity but they didn’t, so we will wait to see the investigation.”

Senior minister in charge of border affairs Var Kimhong said Cambodian and Vietnamese officials would meet on Monday to discuss the border tensions.

The government, which has recently ramped up deportations of illegal Vietnamese migrants, yesterday arrested 10 more in Sihanoukville.