Greenpeace environmental activists have dumped a truckload of coal at the doorstep of France’s presidential palace just hours before a visit by German Chancellor Angela Merkel.

The activist group’s French wing said on its website that the pre-dawn action on Wednesday also involved containers of nuclear waste inside the truck. Images on the site showed police alongside at least four women activists wearing T-shirts written in German and French.

A Paris police spokeswoman declined immediate comment. A presidential palace official wasn’t immediately available for comment.

The stunt raises new questions about security in front of France’s presidential Elysee palace normally guarded visibly by at least several police. Greenpeace France has recently carried out acts including peaceful invasions of French nuclear sites in a bid to expose security dangers.

More In: World | International