PARIS — Greenpeace activists occupied a French nuclear power plant site before dawn Monday — a media stunt deeply embarrassing to the government which is intent on demonstrating that France's reliance on nuclear power is safe.

Around 30 activists from the environmental group invaded state-owned nuclear power utility Electricite de France's Tricastin power plant complex in southern France.

They projected a video on the side of one of the plant's buildings that said "Tricastin Nuclear Accident" and showed the image of a giant crack forming across the building's facade.

Activists also hung a giant banner with President Francois Hollande's face and the words "President of the Catastrophe?"

France's nuclear safety authority said in a statement that so far the intrusion had no impact on the plant's safety.