A helicopter with 18 people on board has ditched west of Sumburgh.
A mayday was issued at about 6.45pm and it is understood the Aberdeen-bound Hjaltland ferry has responded and is heading to the scene.
Lerwick and Aith lifeboats have also been called to the incident. It is believed the helicoter ditched approximately 0.4 nautical miles south-west of Garths Ness.
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.
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 Shetland Coastguard helicopter landed at the Clickimin site at about 7.50pm where it was met by waiting ambulance crews. It is not yet known how many casualties there are.