A search is ongoing for three missing people following a helicopter crash west of Sumburgh this evening.
Lerwick and Aith lifeboats are taking part in a search for the missing men, as part of a major operation being co-ordinated by the Maritime Coastguard Agency.
Two emergency helicopters have also been sent from Sumburgh Airport to assist in the incident.
Fifteen people have been taken to the Gilbert Bain Hospital following the crash, which occurred at about 6.30pm.
The NorthLink freight vessel Helliar and the Aberdeen-bound Hjaltland had been on the scene but both have since been stood down. A salmon vessel is also assisting in the search.
Meanwhile police have declared the crash a “major incident” which started after the helicopter went down shortly before 6.30pm.
A statement from Police Scotland read: “A total of eighteen people were reported to be onboard the helicopter which went down two miles off the coast of Sumburgh.
“The search is currently ongoing involving a number of agencies, coordinated by MCA, and so far fifteen people have been uplifted to Gilbert Bain Hospital in Lerwick.
“Sumburgh Airport is currently closed to allow emergency services to deal with the ongoing incident.
“A major incident has been declared and agencies are working closely in partnership.”
The helicopter, believed to be a Super Puma L2, is operated by CHC, taking people to and from oil and gas platforms in the North Sea. It was travelling from the Borgsten Dolphin platform, east of Shetland, to Sumburgh.
A statement issued by the company said: “CHC Helicopters can confirm that there has been an incident involving one of our aircraft in the North Sea, approximately two miles off Sumburgh.
“Exact details of the incident, which happened at approximately 6.20pm are not yet known.
“The appropriate authorities have been informed and the company’s Incident Management Team is being mobilised.”
The incident is the second emergency involving an off-shore helicopter in Shetland since last October.
At that time, 19 passengers and crew survived when the Super Puma EC225 ditched off Fair Isle.