The United Kingdom Maritime Trade Operations (UKMTO) said late on Sunday it had received reports of an attack on a vessel near Yemen's port of “Ras Isa” and an investigation was being conducted.
In an advisory issued at 2150 GMT, the UKMTO - part of Britain's Royal Navy - advised mariners to exercise extreme caution in the area.
It put the vessel's position at approximately 23 nautical miles west of Ras Isa oil terminal on the Red Sea, Reuters news agency reported.
More details about the attack and its cause have not yet been released.
MA/PR