Staff at Wylfa power station in north Wales are investigating incidents which led to the station's two reactors being shut down on Sunday morning.

Staff shut down the first reactor just after 0800GMT when an element in the system became loose.

The second reactor shut down automatically when there was an electrical fault in the control room.

A spokesman apologised for the subsequent noise created when the reactor's steam was released.

But he added there was no risk to anyone living in the area or people working at the plant.

Emergency services were not involved and the station will start producing electricity again when the problems have been put right.