Oil spill off Oman from tanker under sanctions against Russia spreads over huge area

CAIRO, Aug. 10 (Reuters) - An oil slick is covering an area of around 390 square kilometres (150 square miles) off the coast of Oman, the country's government said on Monday, after a vessel under sanctions and carrying Russian crude sustained damage.

The Caroline Bezengi's crew first reported difficulties on June 8 off the southern Yemeni port of Mukalla, two maritime security sources said, adding that initial assessments indicated that a blast occurred onboard.

In its first public disclosure of details of the environmental impact, Oman said on Monday it was seeking to tackle the oil leak in its waters near the Hallaniyat Islands off the southern governorate of Dhofar.

A statement from Oman's Environment Authority carried by the Omani state news agency said the oil slick covered approximately 390 square kilometres based on its latest analysis that included satellite imagery.

It said the slick extends northeast of the islands towards the mainland and at its nearest point comes within an estimated seven kilometres of the shore.

An analysis by Reuters of satellite imagery and shipping specialists showed the spill from the stranded 274-metre (900-foot) Caroline Bezengi tanker was still spreading at the end of last month, raising concern about possible environmental damage.

The cause of the damage to the vessel is unclear and Oman did not offer any explanation.

Shipping data showed the ship was loaded with Russian crude prior to the voyage. It last transmitted a signal on public AIS tracking on June 11 off the coast of Yemen.

Russia uses ageing, often poorly maintained tankers in what is referred to as its shadow fleet to circumvent Western sanctions on Russian oil exports.

The European Union and Britain have imposed sanctions on the Caroline Bezengi for what they said was involvement in carrying fuels from Russia.