According to Greenpeace Luxembourg, which posted a video of the breach on their Facebook page, the militants breached the interior perimeter fence of the centre, located in France near the border with Luxembourg, at 5:35am on Thursday. They then lit fireworks close to the spent fuel storage pool.

“They want to show just how fragile and accessible these buildings, which are loaded with radioactivity, are,” Greenpeace Luxembourg posted on Facebook.

EDF, which operates the nuclear power station, issued a press statement on Thursday morning saying that the intruders were immediately detected by site security and a team was dispatched to intercept them at 5:45am.

“The intruders always remained outside the buildings and outside the nuclear zone,” EDF wrote in its statement, adding: “This intrusion had no impact on the safety of the installations. It is a breach of the code of defence, which will give rise to the filing of a complaint.”