Activists from environmental group Greenpeace broke into the French nuclear power station of Tricastin on Monday (July 15) to protest against the use of atomic power.

The activists, dressed in red, broke into the Tricastin plant at dusk on Sunday and unfurled a yellow and black banner on the wall with the words: "Tricastin, nuclear accident – president of the catastrophe?" above a picture of the president, François Hollande.

Greenpeace released a video showing banners and messages projected onto the wall of plant questioning the security of such nuclear installations.

The French interior ministry said that the activists had not entered the sensitive zones of the nuclear plant.

A spokeswoman for EDF denied the activists had reached two of the plant's reactors and said that by 8.30am local time on Monday, 17 of them had been arrested for unauthorised access. Others clung on to metal structures and ladders, she said.

Hollande has pledged to cut the share of nuclear energy in the country's electricity mix to 50% from 75% by 2025.

Presented by Adam Justice