AFP - A Russian-crewed cargo ship last seen two weeks ago has been spotted 400 nautical miles (740 kilometres) off one of the islands in the Cape Verde group, a coastguard source said Friday.

"The Arctic Sea is some 400 nautical miles off one of the islands of Cape Verde, therefore outside its territorial waters," the Cape Verdean official said, without saying which island in the archipelago some 450 kilometres off the coast of Senegal.

"The Cape Verde coastguard is in contact with international agencies and organisations that are continually informing it of the movement and progress of the ship."

The source, who spoke on condition of anonymity, said "when the ship enters in our jurisdiction, we will decide in consultation with our partners what actions to take."

The disappearance of the Arctic Sea, which dropped off the radar in the English Channel on July 28, has sparked intense speculation about its fate, with experts debating whether pirates, a mafia quarrel or a commercial dispute were involved.

The Maltese-flagged ship had been due to arrive in Algeria on August 4 with a cargo of sawn timber.

A European Union spokesman said earlier Friday that the ship appeared to have been attacked twice but not in "traditional" acts of piracy, and Russian warships have been scouring the Atlantic Ocean for the vessel.

EU Commission spokesman Martin Selmayr said "radio calls were apparently received from the ship which had supposedly been under attack twice -- the first time off the Swedish coast and then off the Portuguese coast.

"From information currently available it would seem that these acts, such as they have been reported, have nothing in common with 'traditional' acts of piracy or armed robbery at sea," he said, without going into details.

Swedish police say the ship was hijacked in the Baltic Sea on July 24, when masked men claiming to be anti-drugs police boarded the ship, tied up the crew and searched the vessel. But the men reportedly left after about 12 hours.