ANCHORAGE, Alaska (Reuters) - A Japanese cargo vessel that grounded last week near Dutch Harbor, Alaska, has spilled about 24,000 gallons (90,850 litres) of fuel oil, about twice the amount estimated earlier, U.S. Coast Guard officials said. Surveys of the disabled ship indicate that three of its fuel tanks have been punctured, said Coast Guard Chief Warrant Officer Chris Haley. The vessel, the 386-foot (117 metres) Kuroshima, was blown by high winds into a rock late on Wednesday. Two crew members were killed in the collision. The other 16 crew members on board were rescued by the Coast Guard as gale-force winds buffeted the ship. Initially, officials had believed that only one fuel tank was punctured. But more oil was spotted on Monday after bad weather rocked the ship over the weekend. About 125 emergency workers were at the scene Tuesday trying to prepare the ship for removal of its remaining oil, Haley said. Roughly 150,000 gallons (567,810 litres) of fuel oil was believed to be still on the ship. Workers were constructing holding tanks, checking hose and pump systems and preparing to heat the thick bunker oil, which must be warmed before it can be moved off the ship, Haley said. The Kuroshima was preparing to ship frozen seafood from the nearby port when the accident occurred.