MOSCOW – Four environmental activists were sentenced to seven and 10 days behind bars Monday after being detained near what they alleged to be an illegally built residence for Krasnodar region's governor.

The group of 19 activists attempted a protest in form of a picnic in a forest near construction of the residence on the Black sea near the town Dzhubga, said an activist with the Environmental Watch on North Caucasus Andrei Filimonov.

Activists from the group earlier this month were briefly detained on the Black sea further up the coast as they were investigating a different palatial complex which has been linked with Prime Minister Vladimir Putin.

This time the detainment was followed by arrest and sentence of seven days for three activists, and ten days for the fourth activist, Filimonov told AFP. Activists are convicted of resisting demands of the police.

A video from the scene posted by the group on the Internet shows five policemen twisting the arms of an activist with blood on his face as he cries in pain: "What are your demands?"

The judge on Monday refused the request to add the video footage to the case, or to hear any witnesses, including police officers from the scene, Filimonov said. Journalists were not allowed to the hearing by two guards at the entrance to the courtroom, he said.

"Security guards at the construction site called the police who forcibly rounded us up and drove us to the station although we were on public land," he said. "Later we went back for our cars to find that all tires were flat and the locks had broken matches wedged inside them."

A spokesman for regional police told RIA Novosti that the activists hurt a policeman's finger and did not show their documents.

While there are no publicly available documents linking the construction to Krasnodar region governor Alexander Tkachev, it is known among locals as the "Tkachev dacha", Filimonov said.

The Krasnodar region stretches along Russia's coast of the Black Sea and its city Sochi is to host the Winter Olympic Games in 2014.