Abu Dhabi, United Arab Emirates (CNN) -- An explosion occurred Wednesday aboard a Japanese oil tanker in the Strait of Hormuz near Oman, according to the U.S. Fifth Fleet and Japan's Ministry of Land, Infrastructure, Transport and Tourism.
The Japanese ministry said one person was injured aboard the vessel M. Star, but the U.S. Fifth Fleet, based in Bahrain, said in a statement that no injuries were reported by the ship's master.
The tanker's owner and operator, Mitsui O.S.K. Lines Ltd., said the explosion could have resulted from an attack, as a crew member saw light above the horizon, the ministry said in a statement. However, the Fifth Fleet said the cause of the blast was unknown. Because of its location, the Japanese ministry statement said, the explosion was unlikely to have been caused by oil on the tanker.
However, Capt. Musa Murad, director of the Port of Fujairah, United Arab Emirates, told the state-run Emirates News Agency that the tanker was passing through the strait when it was exposed to a high wave as a result of an earthquake shock.
A search of the U.S. Geological Survey's global earthquake database shows the last earthquake to strike the region was a 4.8-magnitude temblor near the coast of southern Iran on Saturday.
The ship was headed to Fujairah for inspection. Murad told the news agency it was expected to arrive about 5 p.m. (9 a.m ET).
"Initial damage assessment from the ship's owner ... is that one lifeboat was blown off the ship and there is some damage to the starboard hatches," the Fifth Fleet said
While the tanker, which was carrying 31 crew members -- 16 from the Philippines and 15 from India -- and 270,000 tons of oil, was damaged, it was able to continue sailing to Fujairah. No oil was leaking, the ministry said. The tanker was originally heading from the UAE to the port of Chiba, Japan.
The U.S. Navy offered emergency assistance to the vessel, but the ship's master determined it was not needed, the Fifth Fleet said. It added it would continue to monitor the situation and the ship's transit to Fujairah. Navy P-3 aircraft were in contact with the ship's master, the fleet said.
The explosion occurred about at 3:30 Bahrain time (8:30 p.m. Tuesday ET), the Fifth Fleet said. The strait -- a narrow body of water between Oman and Iran, leading from the Gulf of Oman to the Persian Gulf -- remained open.
CNN's Junko Ogura, Caroline Faraj and Vicky Brown contributed to this report.