BERLIN (AP) — Dozens of environmentalists are blocking the entrance to a coal-fired power plant in the German city of Mannheim in protest over the burning of fossil fuels.

Mannheim police said about 40-50 climate activists have been staging the protest since the early hours of Saturday.

Police spokesman Michael Klump said that while most protesters are gathered at the plant's main entrance, several have entered the premises and are blocking a conveyor belt used to transport coal.

German group Ende Gelaende, which has staged numerous demonstrations over the years against coal mines and plants, said its members want the Grosskraftwerk Mannheim shut down because its greenhouse gases emissions contribute to global warming.

The 2,150-megawatt power plant by the banks of the Rhine river is jointly operated by three German utility companies.