Soldiers have been stationed at the site of a roadblock that was manned by environmental activists protesting the planned Stung Cheay Areng dam in Koh Kong province.

Twelve Royal Cambodian Armed Forces (RCAF) officers have been posted on the road at the entrance to the Areng Valley since security forces detained 11 activists on Monday.

Neng Van, RCAF commander in Thma Bang district, said the soldiers had been deployed to guard the road to stop the activists from blocking it again.

“We are guarding [the road] around the clock in order to maintain order and security there, and to avoid the road being blocked, which disturbs the villagers,” he said.

Alex Gonzales-Davidson, founder of NGO Mother Nature, was released shortly after 1am yesterday morning after signing a letter apologising for “parking his car across the road”.

Ten other activists were released by the provincial police at about the same time, officials said.

“We had to make a contract with the authorities, promising to stop doing any activities, but we will still carry out our campaign, because it’s not illegal,” Mother Nature’s Heng Samnang, 21, said.

The authorities confiscated several cameras from the activists on Monday and deleted images and videos of the incident, Mother Nature representatives said.

“Three of our cameras were thrown into the jungle. We’re hearing that the relocation site’s been taken over by soldiers,” Gonzales-Davidson said. “These are people under the pay of [dam builder] Sinohydro . . . We’re not going to let them in regardless of who they are.”

Um Serey Vuth of Sawac Consultants, which has been contracted to carry out an environmental impact assessment at the planned dam site, said he was waiting on authorisation to go back into the valley.

Sam Khitviet, Koh Kong provincial police chief, said that if the campaign continued, the activists could face “tough measures”.

The Cambodian Youth Network issued a statement yesterday condemning the arrests as “an act of intimidation on the protesters who work to preserve the forest and natural resources”.