Tensions continued to rise between Cambodia and Vietnam yesterday, with both countries firing off statements over recent border disputes, including fierce comments from Hanoi blaming Cambodian “extremists” for violent clashes with Vietnamese authorities in disputed territory on Sunday.

In Vietnam’s strongest remarks yet on the recent border dramas, Foreign Ministry spokesman Le Hai Binh blasted Cambodians involved in the brawl, which erupted after opposition lawmakers led a 250-strong group to “inspect” the alleged encroachment of a Vietnamese-built road in Svay Rieng province’s Kampong Ro district.

Binh said the “extremist” group illegally entered Vietnam’s Long An province and instigated the attack, which, he added, contravened both countries’ laws and treaties, threatened the nations’ relationship and jeopardised the ongoing demarcation process.

“Vietnamese security officers and local residents tried to reason with the activists and stop them, but they were attacked … seven Vietnamese were injured,” Binh said, in a statement published yesterday.

“We request Cambodian agencies to deploy measures to settle the incident and prevent similar actions from happening again to ensure the smooth implementation of border delimitation and marker planting for the common interest of both peoples.”

More than a dozen people were injured in the brawl, which was condemned by Svay Rieng provincial authorities.

Footage online shows a crowd of Cambodian activists waving flags, shouting and trying to push past Vietnamese border guards.

It was the latest of several trips to the border by Cambodia National Rescue Party lawmakers last month, which have fuelled the sensitive, long-running issue by highlighting examples of alleged Vietnamese encroachment.

In response, the Cambodian government – which this morning was to hold a press conference on the topic – has toughened its public stance with its neighbour.

Yesterday, the Ministry of Foreign Affairs issued its third diplomatic note in the last month to Hanoi to protest alleged violations, which include the building of irrigation ponds and a military post in Ratanakkiri and Kandal provinces, respectively.

The statement, sent to the Vietnamese Embassy in Phnom Penh, demanded Hanoi cease building roads and infrastructure in areas yet to be demarcated and requested Vietnam provide a map detailing any planned construction in unresolved border areas.

It cited three sections of road in Svay Rieng province, one in Chatrea and two in Kampong Ro, the construction of which should stop “as early as possible”.

The notice came as the senior minister in charge of border affairs, Va Kimhong, announced a joint Cambodia-Vietnam Border Committee meeting next week in Siem Reap.

Between July 6 and 9, Kimhong said 20 senior officials from each country would address Sunday’s violence as well as the border’s ongoing demarcation.

The CNRP, however, will not be invited to participate, Kimhong said, adding that the opposition’s antics were delaying the demarcation process that, he said, had no set completion date.

“Tell the opposition party not to bother us [and] we will set up [the border posts] quickly,” Kimhong said.

Although welcoming the government’s firmer line of late, CNRP lawmaker Um Sam An, one of two lawmakers involved in Sunday’s brawl, said the opposition’s exclusion from the border committee compromised the demarcation process’s transparency.

Sam An also labelled the protest notes ineffective, urging the government to contest Vietnam’s encroachment at the International Court of Justice. He went on to reject Vietnamese accusations that his group had sparked the violence on Sunday.

“The extremists are the Vietnamese who entered Khmer land,” Um Sam An said.

Jon Grevatt, Asia-Pacific industry reporter for defence analyst IHS Jane’s, said the countries’ close military and economic ties likely precluded any serious conflict.

“I don’t think it will escalate, the relationship between the two countries fundamentally is much stronger than it used to be.”

ADDITIONAL REPORTING BY AFP