Activists dressed as bears and holding placards reading "this is my home" protested Tuesday plans to build a highway in Romania they say would cut into one Europe's last intact forests.

"We are going to defend it (the forest) with our bodies, we will not allow concrete mixers and saws to enter," president of the Agent Green nongovernment organisation, Gabriel Paun, told AFP.

The group is part of a "resistance camp" set up in the western village of Campusel, near where the new road is planned into Domogled-Valea Cernei national park. More than 20 activists have camped there since Thursday.

"This would destroy the habitat for big mammals that live here, bears, wolves and lynx, and for other animals, birds, reptiles, amphibians and even fish," Paun said.

The road project has been frozen by court action, with activists rejecting as superficial an environmental impact study for the national 66A highway.

Several NGOs including world environmental body WWF have started a new study.

But they fear construction could start in the absence of authorisation, alleging this was the case with another section of road that was finished in 2007 and crosses a part of the Retezat national park.

WWF says the road 66A would cut into the last intact forest landscape in Europe outside Russia and Finland.