The German authorities on Wednesday suspended an operation to evict protesters, holed up in forest treehouses to block the expansion of an open-pit coal mine, after the death of a journalist.
The man, "most likely a journalist" according to the police, died on Wednesday after falling from a bridge that connected two of the treehouses.
"We simply cannot continue as if nothing has happened," North Rhine-Westphalia Regional Minister Herbert Reul told a press conference.
A website of the forest activists said that "a friend who has accompanied us as a journalist for a long time in the forest, fell today from a suspension bridge over 20 meters high in Beechtown and died".
Police officers have faced fierce resistance since the middle of last week while attempting to clear the demonstrators from Hambach Forest near the border with Belgium and the Netherlands.
On Sunday, nine environmental activists were injured and 34 detained as part of the operation to remove dozens of treehouses, some as high as 25 metres (80 feet) off the ground.
The occupation began in 2012 and had until now been quietly tolerated.
But local authorities have now ordered the woods to be cleared immediately, citing fire hazards.
The death of the journalist was a "tragic accident" and not "related to the ongoing evacuation work," said the police.
The activists, who are protesting the expansion of energy giant RWE's open-pit lignite mine, one of Europe's largest, had called for a mass mobilisation by supporters to prevent the forest from being cleared.
The battle has intensified since RWE announced plans to clear half of the forest's remaining 200 hectares (500 acres) from mid-October.
RWE owns the forest and is legally allowed to cut down trees to access the brown coal, or lignite, in the ground during the annual logging season.
It says the clearing is necessary to ensure energy supply, including of nearby power plants in Germany's most populous state, North Rhine-Westphalia.
Activists oppose the use of the cheap but polluting fuel, and say the forest is home to protected species such as Bechstein's bat and century-old beech and oak trees.