An explosion at a nuclear power station in northern France on Thursday caused minor injuries but happened outside the plant's nuclear zone and posed no risk of contamination, authorities said.

According to a report in Telegraph, five persons were injured after inhaling smoke from the explosion.

"It is a significant technical event but it is not a nuclear accident," senior local official Olivier Marmion told AFP following the blast at the Flamanville plant 25 kilometres (15 miles) west of Cherbourg.

Since there is no risk of contamination, the emergency intervention plan to protect local residents in case of a leak, has not been triggered, The Local France reported. However, one of the plant's reactors has been shut down as a precautionary measure. 

Owned by Électricité de France (EDF), a French electric utility company with headquarters in Paris, the plant is located in the Flamanville commune and has two pressurized nuclear water reactors producing 1.3 GWe (gigawatt electrical)  each, Russia Today reported. A third reactor is being built now.