BAGHDAD (AP) — Iraqi explosives experts were working to defuse a large mine discovered on an oil tanker in the Persian Gulf and evacuate its crew, authorities said Friday. The statement came a day after two private security firms said sailors feared they had found a limpet mine on the MT Pola, a Liberian-flagged tanker in the waters off the Iraqi port of Basra. A limpet mine is a type of naval mine that attaches to the side of a ship, usually by a diver-member of special forces. It later explodes, and can significantly damage a vessel. The Iraqi statement said the mine had been attached to a tanker rented from Iraq’s Oil Marketing Company SOMO that was refueling another vessel. Iraq’s naval forces were making “a great effort to accomplish the mission” safely, said Iraq's Security Media Cell, which is affiliated with the country’s security forces.