A tanker was struck by an unknown projectile while transiting the Strait of Hormuz on Thursday, causing a fire aboard the vessel, the UK Maritime Trade Operations said.
The organization said it received a third-party report of the incident at 1750GMT.
The crew was reported safe, while the extent of damage to the tanker and any environmental impact remained unknown, it said.
Earlier, Iran's semi-official Fars News Agency, citing local sources, reported that a supertanker with a capacity of 2.5 million barrels had been hit about 8 kilometers (5 miles) off the Omani coast and was on fire.
Fars said the vessel had been sailing on an "unauthorized route" through the Strait of Hormuz.
