Six people are missing after a civilian helicopter crashed in the North Sea.
A rescue operation involving RAF air crews and lifeboats is now under way off Great Yarmouth.
The routine flight was ferrying oil workers when it crashed.
Five casualties were pulled from the water within an hour of the mayday call. Their condition is not yet known.
A Seaking helicopter from RAF Wattisham in Suffolk has taken the workers to the Santa Fe Monarch oil rig 25 miles north east of Great Yarmouth.
RAF Flight Sergeant Mr Adrian Osbourne said: "The aircraft which ditched into the water is floating. One search and rescue helicopter from Washington is combing the sea at the moment.
"So far five casualties have been recovered and we are searching for another six."
A spokesman for RAF Kinloss added: "It is too early to speculate what happened the weather conditions were pretty benign out there."
PA