Activists had chained themselves to rail tracks on which the coal is brought to the power plant. The police were able to cut the chains and the concrete-filled pipes and clear the tracks.

There was no further unrest during the night, a police spokesman in Aachen said.

On Saturday morning, 26 people were still in police custody. Eleven of them were to be brought before judges to determine whether they will remain in detention.

The protest was prompted by the COP26 world climate conference in the Scottish city of Glasgow.

“The world climate conference has been taking place for 26 years. Since then, CO2 emissions have increased by 60 per cent. We need more than empty promises,” said a spokesperson for Block Neurath, the group that organized the protest.

Further demonstration by activists are planned throughout Germany in the first half of November to coincide with the climate negotiations.

Lignite-fired power plants are considered Europe’s largest producers of climate-damaging carbon dioxide.