Greta Thunberg joined thousands of demonstrators to march in a large-scale protest in Germany against the demolition of a village to make way for an opencast coalmine extension. Crowds of activists marched on the hamlet of Lützerath in western Germany, waving banners, chanting and accompanied by a brass band, but there were also violent clashes with police. Thunberg marched at the front of the procession as demonstrators converged on the village, showing support for activists occupying it in protest over the coalmine extension. Local media reported stones being thrown at police. One demonstrator was seen with a head injury, as ambulance sirens sounded near the protest site. “Germany is really embarrassing itself right now,” the climate activist said before the protest on Saturday. She described the force used by police in their clearance of the protest camp earlier this week as “outrageous”. “When the government and corporations act like this, destroying the environment … the people step up,” she said. Demonstrators have occupied the village in the brown-coal district of the western state of North Rhine-Westphalia for two years, trying to stop the expansion of the nearby lignite mine run by energy firm RWE. Some built elaborate treehouses. The German government and RWE argue the extra coal is needed to ensure the country’s energy security. However, a study by the German Institute for Economic Research has questioned this, suggesting other existing coalfields could be used instead – although RWE’s costs would be higher. After a decision allowing RWE to proceed with the expansion, reports suggested more than 1,000 police in riot gear evicted hundreds of demonstrators from the village earlier this week. Some protesters threw fireworks, bottles and stones at police as they entered on Wednesday morning. Others complained of undue force and said the scale of the police response, with officers brought in from other areas of Germany and water cannon put on standby, was an unjustified escalation. A police spokesperson said the attacks on officers were “not nice” but claimed most of the protest had been peaceful. The local police chief rejected Thunberg’s criticism. Just two protesters – nicknamed Pinky and Brain – remain holed up in a tunnel. “The science is clear: we need to keep the carbon in the ground,” Thunberg told reporters, after meeting protesters and touring the mine’s crater. She compared the landscape of the mining area to Mordor, the fictional realm of the evil villain Sauron in JRR Tolkein’s Lord of the Rings. “It shows what we are fighting against, what we are trying to prevent.”