Environmental activists have stormed a lignite mine in western Germany to protest the use of coal, a major source of greenhouse gases.

The German news agency dpa reports that several hundred people from a group calling itself EndeGelaende — which loosely translates as "it's finished now" — broke through a police line in Garzweiler, west of Cologne.

Police spokesman Anton Hamacher says officers used pepper spray to stop the crowd and are removing protesters from the site.

A spokesman for German energy company RWE says several huge bucket-wheel excavators used at the open-pit mine had to be shut down for safety reasons. Spokesman Lothar Lambertz says RWE has canceled plans to bring employees onto the site to rally in favor of coal mining.