All UK commercial passenger flights using the Airbus EC225LP helicopter have been grounded by the Civil Aviation Authority (CAA) following a fatal crash in Norway.
One Briton is among the 11 people killed after the aircraft, also known as a Super Puma, came down near the city of Bergen on Friday. Two people remain missing, but are feared dead.
The CAA said in a statement: "Following the accident the UK CAA has issued an instruction to stop any commercial passenger flights by UK operators flying the Airbus EC225LP helicopter. This mirrors action taken by the Norwegian CAA. The restriction does not apply to search and rescue flights.
"The accident involved a Norwegian helicopter and will therefore be investigated by the Norwegian authorities. We will offer any assistance that we can."
The helicopter was carrying passengers from the Gullfaks B oil field in the North Sea when it came down near the small island of Turoey.
Those on board also included 11 Norwegians and one Italian.
A spokesman for Norway's Joint Rescue Co-ordination Centre (JRCC) confirmed 11 bodies have been found.
The CAA's decision to ground all commercial Super Puma flights by UK operators comes after four people died when one crashed in the North Sea in August 2013, while 16 lives were lost in an accident in April 2009.
In February 2014 the Civil Aviation Authority introduced a series of measures to improve the safety of North Sea helicopter operations.
The changes included prohibiting flights in the most severe weather conditions, amending the seating of passengers, improving breathing equipment and altering the training of pilots.
The Foreign and Commonwealth Office confirmed the British fatality, saying in a statement: "We have offered our support to the family of a British national who has sadly died in a helicopter crash in Bergen, Norway.
"Our thoughts are with all those affected. We will remain in contact with local authorities."
Broadcaster NRK reported that 11 of those on board were employed by Norwegian oil and gas company Statoil ASA.
Police spokesman Morten Kronen told the Associated Press that the helicopter was "totally smashed".
Television footage showed smoke billowing from the crash site.
Eyewitness Rebecca Andersen told Norwegian newspaper Verdens Gang that the helicopter's rotor blades "came rushing toward us", before she heard "a violent explosion".
Norwegian prime minister Erna Solberg posted a message on Twitter which described the incident as "horrifying".
A team from the UK's Air Accidents Investigation Branch (AAIB) will travel to Norway on Saturday to assist with the investigation because it has carried out inquiries into several crashes involving helicopters operating to and from offshore oil and gas fields in recent years.
The Norwegian Civil Aviation Authority said the crashed helicopter's flight recorders, the so-called black boxes, have been recovered.
Spokeswoman Hege Aalstad said that the boxes had been found but did not give any further details.
The flight data recorder and the cockpit voice recorder could help explain what caused the crash.