HAMBACH, Germany (Reuters) - German riot police cleared environmental activists from treehouses in an ancient forest on Thursday, dismantling a protest camp set up five years ago to block a coal mining project.

Wearing helmets and carrying shields, they used a hydraulic platform mounted on a truck to force activists from the treehouses erected in Hambach forest, west of the city of Cologne.

Officers carried off some of the protesters who were trying to prevent utility RWE from clearing the forest that it bought decades ago to expand mining in the area. Most of the forest has already been chopped down and the activists were trying to save a remaining patch of green.

The activists had asked RWE to delay the logging until a year-end deadline for a commission to submit plans to the government for Germany to give up coal-fired energy.

Germany aims to raise wind and solar power’s share of energy generation from a third now to 65 percent by 2030 to help to cut carbon dioxide emissions and achieve its climate commitments.

Police said measures were being taken to prevent the activists from returning to the site. “After the operation we will monitor people and vehicles trying to come here in order to prevent the reconstruction of what we so painfully dismantled,” said police spokesman Paul Kemen.