RIYADH, July 28 (Xinhua) -- The vital Strait of Hormuz shipping lane remained open for navigation on Wednesday after an explosion hit a Japanese oil tanker near the passage, the U.S. Navy said.

　　"The Strait of Hormuz remains open for safe navigation and shipping lanes are unaffected by this incident," a statement by the Bahrain-based U.S. Fifth Fleet said.

　　"The cause of the explosion and extent of damage is currently unknown," the statement said.

　　Japan's transport ministry said that Japanese oil tanker M. Star blasted near the Strait of Hormuz on Wednesday, leaving one person slightly injured.

　　"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 Fifth Fleet said.

　　The crude oil tanker M. Star was damaged but the engine was not affected by the blast, Kenji Yoshimura, a publicity official of the Mitsui O.S.K. Lines Ltd., owner of the ship, told Xinhua. The explosion did not lead to an oil leakage, he said.

　　An earlier report by Kyodo news agency quoted the owner of the ship, Mitsui O.S.K. Lines Ltd as saying that the tanker might have been attacked by an outside force.

　　A total of 31 Indian and Filipino crew members were aboard the ship, the official said, adding 15 are Indians and 16 are of Philippine nationality. The injured one was Indian.

　　The explosion occurred at about 00:30 a.m. Wednesday local time when the ship was sailing in Oman waters in the western part of the strait.

　　The tanker was heading toward Japan after loading crude oil in the port of Das Island in Abu Dhabi of the United Arab Emirates when the blast took place, Yoshimura said.

　　The tanker is now on its way toward the port of Fujairah in the United Arab Emirates for a checkup and the investigation of the causes.