About 6,000 protesters, including climate activist Greta Tunberg, marched through mud and rain to the German village of Lutzerath on Saturday, according to police estimates, protesting the expansion of an open-pit brown coal mine, Reuters reported.

The clearing of the village in the western state of North Rhine-Westphalia was negotiated between RWE and the government as part of a deal that allowed the energy giant to demolish Lutzerath in exchange for accelerated coal abandonment and saving five villages originally slated for destruction.

"This is a betrayal of present and fuure generations... Germany is one of the biggest polluters in the world and needs to be held accountable," Thunberg said on a podium, after she marched with a cardboard sign saying in German "Luetzi stays", using a shortened name of the village.

As protesters approached the village, they were confronted by police, some using batons to push protesters back.

Regional police said on Twitter that they used force to stop people who broke through barriers and approached the danger zone at the edge of the excavation.

Earlier this week, police kicked protesters out of buildings they had occupied for nearly two years in an attempt to stop the expansion of a nearby mine.

The head of the state of North Rhine-Westphalia told German radio Deutschlandfunk on Saturday that energy policy is "not always pretty," but coal is needed more than ever in light of the energy crisis facing Europe's largest economy.

Earlier, Economy Minister Robert Habeck told Spiegel on Friday that Lutzerat was the "wrong symbol" to protest.

But activists said Germany should no longer extract lignite and should instead focus on expanding renewable energy sources.