By Associated Press – 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 Lambertzsays RWE has canceled plans to bring employees onto the site to rally in favor of coal mining.