28 July 2010 Last updated at 15:43 GMT
A Japanese oil tanker has been damaged in an incident in the Strait of Hormuz near Oman, injuring crew members.
An early report from the Japanese transport ministry said there had been an explosion on board the ship which could have been an attack. But a port official in the United Arab Emirates says the vessel was hit by a freak wave, triggered by a small earthquake.
There are no reports of any oil leaking from the tanker, the M Star. The vessel, with 16 Filipino and 15 Indian crew members on board, had been bound for Chiba port near Tokyo when the incident occurred.
Several of the crew were injured in the incident, according to an official at the port of Fujairah in the UAE, where the ship was due to dock to have its damage assessed. "The cause of the incident was a freak wave and there is damage in the upper accommodation decks of the ship and a few injured people on board," he told Reuters news agency.
"The ship is not being tugged and there is no damage to the engine." Oman's coastguard cited "a tremor" as the cause of the incident. A seismologist in nearby Iran said an earthquake of magnitude 3.4 happened in Bandar Abbas.
Captains of other ships near the incident also mentioned the earthquake, Attollah Sadr, head of Iran's Ports and Maritime Organisation, was quoted as saying by Mehr news agency. The Strait of Hormuz links the ports of oil-rich states such as Saudi Arabia and Kuwait with export markets. About 40% of the world's traded oil passes through it.
The M Star was loaded with some two million barrels of crude oil when the incident occurred, said Japan's Mitsui OSK, which owns and operates the vessel. Earlier, Japan's transport ministry issued a statement saying an "explosion" had occurred at around 0030 local time (2030 GMT). "A crew member saw light on the horizon just before the explosion, so ship owner Mitsui OSK believes there is a possibility it was caused by an outside attack," the ministry had said.