Work by military engineers on a contentious road skirting Cambodia’s border with Laos – which has prompted a military stand-off in the area – has quietly resumed, local officials say, even as run-ins between Cambodian and Lao military patrols in the disputed area have further heightened tensions.

For about 40 kilometres, the Sekong River forms a natural barrier between the two countries, but according to two officers posted to the area, Lao forces have hung signs from trees south of the river urging a halt to construction and warning “This is Laos”. Cambodia, however, strongly disagrees.

Returning on Saturday from the disputed area, Meas Chan, a captain in the Royal Cambodian Armed Forces’ Engineering Unit 701, said his squad had been providing protection for troops checking for landmines and clearing forest to make way for the road along the south of the Sekong in the northern tip of Stung Treng’s Siem Pang district.

Chan said work had resumed in March after authorities announced a halt in late February following a show of force by Lao armed forces, which sent troops across the river to demand the work cease.

He said engineers were now withdrawing for a break over the Khmer New Year.

“We continue to build [the road] but now there is a temporary stop,” he said, saying several units had been sent to protect workers.

“If the engineers did it alone, they would not allow us to do it. Laos has asked four times for a suspension. [On April 7] A Laotian commander came to negotiate from [Laos’s] Attapeu provincial military.”

Laos claims the road, which will run along the border into Ratanakkiri province, effectively hemming in Virachey National Park, crossing into an undemarcated zone. Chan, reading from notes from the meeting with the Lao officials, said the Laotian commander made three demands on Friday: delay clearing, do not bring weapons to solve the problem and inform Laotian authorities before crossing the river.

Reached yesterday, Stung Treng provincial military commander Svay Nhan confirmed work had restarted on March 26 and would resume after Khmer New Year. “When Laos prevents us we stop, but when [the confrontation finishes] we continue to go forward,” Nhan said, saying he believed this tentative approach would not lead to a conflict.

The disputed site is on the south side of the Sekong, about 10 kilometres east of where the river veers south into Cambodian territory.

Since the heightened tensions, Cambodia has bolstered its forward post to include a total of 20 border policemen in the area and an unknown number of soldiers from the military’s Region 1 across about four or five positions, according to the deputy chief of Koh Russei border protection police, Seak Samneang, who had recently rotated away from the site.

They also have four artillery guns placed on high ground, said Samneang.

“[Laos] claims it is their land, but this is impossible,” added Samneang, who said clearing work had progressed about 3 kilometres past 30 to 40 dugouts created by Laotian troops near the road after the initial suspension.

Samneang said the engineers were nearing what he and Meas Chan, from the 701 engineering unit, described as a gem mine. “It’s like the mines in Pailin province,” he said. “About 5 metres deep, dug by hand.”

Chan said Laotian civilians had worked the mine, though Samneang said he had not seen any miners in the area. He said the area was resource-rich, and he allowed that access to its minerals and timber could be a factor in the dispute.

“Mostly the Laotians come across [the river] to get the luxury timber. I think there are a lot of resources because Cambodia hasn’t had the equipment to take them out . . . There was no road there before,” he said.

Efforts to reach the area over the weekend were unsuccessful.

After travelling for about 10 kilometres on the recently-cut dirt road, which rises and falls through steep gullies and runs between the Sekong River and Virachey park, reporters were stopped by two patrolling Cambodian soldiers and told the area was off-limits to civilians.

“Go back now,” demanded the soldier, who would only say there were a “substantial” number of Cambodian troops in the area.

Samneang said Laos had a base on the northern side of the river with between 60 and 70 troops but his team had twice intercepted Laotian patrols south of the river, one in February and another later in March.

In the first encounter he said some 35 Cambodia policemen and troops had surrounded about 10 Laotians and escorted them back to their three wooden boats. “We spotted them at about 2pm or 3pm and ran to hide in positions around the forest. We surrounded them and they put their hands up. They saw we had many people. Our commander speaks Lao and went to shake their hand.”

The second confrontation, later in March, involved about 12 Cambodian personnel and five Laotians. “We were walking and bumped into each other,” said the officer, who said the tense encounter, in which both sides had their weapons raised, was again reined in by their Lao-speaking commander before the Laotians were escorted back to a single boat.

Provincial authorities were unreachable yesterday, though the provincial governor of Stung Treng and his Laotian counterpart from Attapeu are set to meet after Khmer New Year. The meeting is set to revolve around recent frictions, which also stem from new construction at border-side outposts near the international checkpoints, some 70 kilometres southwest of the contentious road in Siem Pang district. Officials posted to those areas told The Post they believe the road in Siem Pang is the main source of tension, which was in turn spilling over to other yet-to-be-demarcated areas of the border.

At a local crossing in O’Svay commune, about 30 Laotian troops arrived on April 2 to halt Cambodia’s attempt to build a small shelter on a yet-to-be demarcated site, which itself was a response to Laos’s attempt to upgrade a small post next to the border in nearby Samaki commune.

A border policeman at that post, who requested anonymity to discuss the stand-off, said he asked the Laotians why they were now claiming the area, which is about 400 metres from their checkpoint, was their territory.

“They said ‘this is the order from our leaders’,” he recalled.