Libya’s coast guard said Thursday it had intercepted a Russian-flagged tanker suspected of carrying an illegal shipment of petrol and detained 12 crew members from Russia.

Libya's coast guard said Thursday it had intercepted a Russian-flagged tanker suspected of carrying an illegal shipment of petrol and detained 12 crew members from Russia.

"We received a signal on the presence of a ship transporting an illegal cargo of petrol near Zuwara," 160 kilometers (100 miles) west of Tripoli, on Wednesday, Captain Taoufik Mohamad Assakir, operations chief for central Libya, told AFP.

The ship loaded with five million litres (one million gallons) of petrol was boarded 14 nautical miles off Zuwara and diverted to the naval base in Tripoli, he said.

The captain said its 12 Russian crew, including a woman, were detained.

Moscow said it was working to secure the release of the Russian nationals.

"Our embassy is currently in contact with local authorities and is clarifying the fate of our crew," Russian foreign ministry spokeswoman Maria Zakharova told reporters.

In March 2014, the US Navy intercepted and boarded the North Korean tanker "Morning Glory" loaded with an illegal oil shipment in the eastern Mediterranean and escorted it back to Libya, although it later escaped back to sea.

Libya has been plunged into insecurity and chaos since dictator Moammar Gaddafi's ouster in a 2011 revolution, torn between an administration in Tripoli and the internationally recognized government in the oil-rich country's far east.