U.S. Navy says cause of Japan tanker explosion unknown

MANAMA, July 28 (Reuters) - The U.S. Navy said on Wednesday that the cause of an explosion aboard a Japanese supertanker passing through a strategic Gulf shipping lane was unknown.

"Initial damage assessment from the ship's owner, Mitsui O.S.K. Lines Ltd, Japan, is that one life boat was blown off the ship and there is some damage to the starboard hatches," the U.S. Fifth Fleet, which is based in Bahrain, said in a statement.

"The cause of the explosion and extent of damage is currently unknown," it added. (Reporting by Frederik Richter; Editing by Amran Abocar)