DUBAI—The U.S. Navy is assisting an Israeli-managed petroleum products tanker that was fatally attacked on Thursday off the coast of Oman, the U.S. military said on Saturday, adding the ship was most likely hit by a drone strike. The Mercer Street, a Liberian-flagged, Japanese-owned vessel, is currently being escorted by the aircraft carrier USS Ronald Reagan, the U.S. Central Command said in a statement. “U.S. Navy explosives experts are aboard to ensure there is no additional danger to the crew, and are prepared to support an investigation into the attack,” said the Central Command, which oversees American military operations in the Middle East and Central Asia. “Initial indications clearly point to a UAV-style (drone) attack,” it added. Israel’s foreign minister blamed Iran on Friday for the attack, which killed two crewmen, a British and a Romanian. U.S. and European sources familiar with intelligence reporting said on Friday Iran was their …