Mogadishu: At least four foreign crew members and seven Somali pirates died when a cargo ship that the pirates were holding to ransom off the Somali coast sank on Sunday, and 13 others were missing, a pirate who works with the gang said.

The Malaysian-owned MV Albedo cargo vessel and its crew were hijacked 1,448km off Somalia on November 26, 2010 while sailing from the UAE to Kenya.

“The ship has been gradually sinking for almost a week, but it sank totally last night,” the pirate said on Monday by telephone from Haradheere, Somalia’s main pirate base.

“We have confirmed that four foreign [crew] and seven pirates died. We are missing 13 in total,” said the pirate, who gave his name as Hussain. “We had no boats to save them.” The Albedo had 23 crew from Pakistan, Bangladesh, Sri Lanka and Iran when it was seized.

Hussain said the captain had died earlier and four of the crew had previously been taken off the ship. With four dead, this would leave 14 to be accounted for, and it was not clear why there was a discrepancy with the pirates’ figures.

The EU Naval Force, a European Union anti-piracy unit that protects merchant shipping off the Horn of Africa, said the whereabouts of 15 crew were still unclear.

“EU Naval Force can confirm that the Malaysian flagged motor vessel MV Albedo, held by armed pirates at an anchorage close to the Somali coast, has sunk in rough seas,” a statement on the force’s website said.

“An EU Naval Force warship and Maritime Patrol Aircraft have closed the sea area and are carrying out a search and rescue operation to search for any survivors. The whereabouts of the 15 crew members from MV Albedo is still to be confirmed.” Some hostages are held on land while pirates demand ransoms from ship owners, with some kept onboard to maintain the ships.

The number of attacks by Somali pirates has fallen over the last two years due to increased naval patrols and the presence of well-armed security teams on ships.

The local administration said the Albedo had been the last ship held off Haradheere, because it had convinced many pirates to quit the business and given them training in legal trades.

But piracy emanating from the lawless Horn of Africa may still cost the world economy about $18 billion (Dh66 billion) a year, the World Bank said in a report in April.