Thousands of people joined climate change protests near one of Germany's biggest lignite coal mines on Saturday, two days after European Union leaders failed to agree on a plan to make the bloc's economy carbon neutral by 2050.

German police deployed hundreds of officers in and around the western German village of Hochneukirch to prevent demonstrators from blocking the vast, open-pit mine and adjacent power plants.

Environmental activists walk to the site of the Garzweiler open-cast mine. Credit:dpa

Hundreds of protesters succeeded in temporarily blocking railroad tracks used to transport coal and another group broke through a police cordon and entered the mine, German news agency dpa reported. The various rallies were mostly peaceful.

The mine has become a focus of environmental protests in recent years because the operator, German utility company RWE, threatened to chop down a nearby forest to enlarge it.