A Mayday radio shout has sparked a coastguard search of the sea around Orkney.

The call was heard on the VHF marine radio channel on Tuesday morning but no further information was relayed.

It prompted the coastguard search in the Scapa Flow area at around 7.20am, while lifeboats from RNLI Stromness and RNLI Longhope also attended.

They were stood down at 10.35am after failing to find any vessels in difficulty before a fishing boat based in Kirkwall informed the coastguard it had heard the original Mayday shout "loud and clear".

The coastguard's helicopter based at Sumburgh has been deployed and is currently searching the coast around Kirkwall and Shapinsay.

A coastguard spokeswoman said: "At 7.20am today a spoken word Mayday was heard on the Orkney VHF aerial on Channel 16. No more information was heard aside from Mayday.

"UK Coastguard immediately issued a relay broadcast to vessels in the area asking if they had heard the Mayday to ascertain the strength of the signal and what area it might have originated from."

She added:"Following further information from a fishing vessel in Kirkwall who heard the Mayday loud and clear, the UK Coastguard search and rescue helicopter based at Sumburgh was sent to the Kirkwall and Shapinsay area to carry out a coastal search. This part of the search remains ongoing."