Activists have lived in the trees for the past six years as part of a protest to protect the forest from coal mining. But now the authorities have said the treehouses violate building codes and are a fire hazard.
Authorities in the western German state of North Rhine-Westphalia (NRW) have ordered the "illegal" treehouses in Hambach Forest to be taken down with immediate effect, citing safety concerns.
The activists were ordered to vacate the treehouses on Thursday morning, with police giving them 30 minutes time before moving in. Journalists were also blocked from entering the area where the structures are located after police cordoned it off.
Police and several vehicles were deployed to the scene, including an armored vehicle with a plow on the front and a water cannon.
The authorities subsequently removed the first group of protesters who were participating in a sit-in, according to the DPA news agency. The protesters did not resist, and were dragged away by the police. One activist was roughly thrown to the ground by police, according to video taken by a reporter for German public broadcaster WDR.
Police used cranes to try and reach activists who were sitting in raised platforms dubbed "tripods," reported DW's Helena Kaschel, who also noted that one treehouse village called "Oaktown" remained undisturbed by midday.
The state's Construction Ministry said the structures occupied by anti-coal activists are a fire hazard and do not conform to building regulations. They do not have emergency stairs and lack access routes for fire brigades and ambulances.
The 30 to 60 treehouses have come to symbolize the resistance to coal mining in the region. The activists living in them for the past six years are fighting to protect the forest from being razed as part of an expansion of an opencast mine to extract lignite, or brown coal, one of the dirtiest fossil fuels.
Authorities expect it will take days to fully clear out the forest. It remains to be seen whether several last-minute legal petitions filed in courts in Aachen and Cologne will be able to halt the evacuation operation.
Last stand against coal mine
The RWE energy company, which owns the forest, intends to clear some 100 hectares (247 acres) of land to expand the nearby Hambach mine, already Europe's biggest open pit coal mine. But its efforts have been frustrated by the activists occupying the forest.
RWE has been given permission to begin clearing the forest from the start of October. The energy company argued that it is "absolutely necessary in the short term" in order to secure coal production from the mine.
Dozens of protesters were expelled from the forest earlier this month after several hundred German police officers accompanied RWE workers tasked with clearing the forest. RWE staff also began removing forest logs and other obstacles, which were meant to keep police and workers from accessing certain areas.
Police clear Hambach Forest
NRW Premier Armin Laschet described the treehouses as "illegally occupied areas," adding that police officers have been attacked from those structures for days.
Laschet said RWE had the right to clear the forest.
"The state government is there to ensure that the law that applies is enforced," he said during a talk show on WDR.
Activists pledge 'country-wide mass mobilization'
The international environmental group Greenpeace urged German Chancellor Angela Merkel to "deescalate and stop further removals," accusing the state government of acting on behalf of the RWE energy firm.
Several protester associations pledged to start a "country-wide mass mobilization" on Thursday in order to prevent the removal of the tree houses.
According to activist Jan Pütz, the protesters will take part in "mass civil disobedience" at the site during the weekend.
"With this type of action, we are taking our future in our own hands," he said.