Tonnes of oil is to be removed from a cargo ship which ran aground in the Pentland Firth.

The MV Priscilla is stranded on the Pentland Skerries off the Caithness coast after running aground early on Wednesday, July 18.

The six crew on board are said to be safe and well and the coastguard said the 89m vessel is in "stable position" but stuck hard aground.

Experts working on a salvage plan have now agreed to remove up 35 tonnes of the marine gas oil it is carrying.

The coastguard said the ship did not sustain major damage and there are no signs of pollution but the oil removal is "precautionary measure" ahead of a further attempt at refloating after previous attempts were unsuccessful.

Part of the ship's 3300 tonne cargo of fertiliser will also be removed during the salvage operation, which has been approved by Hugh Shaw, the secretary of state's representative for Maritime Salvage & Intervention.

A Maritime and Coastguard Agency spokeswoman said around 1350 tonnes of cargo will be removed onto barges then loaded onto a waiting cargo ship.

Pressurised air will be pumped into the ship's tanks, ballast removed and an attempt will be made to refloat the vessel on high water.

If successful, a brief inspection will take place before the ship is towed to safe location for more in-depth investigations.

A temporary exclusion zone around the vessel has been doubled to 1000 metres in advance of the salvage operation commencing.