The UK's Maritime Trade Operations Agency said on Friday it had received reports of a ship being attacked south of the coastal village of Nishtun in Yemen's Al-Mahra province.
The agency said in a statement that shots were fired at the ship from 3 ships involved in the attack, each with 3 or 4 people on board.
The report comes a day after Iran said it had seized a U.S.-bound oil tanker in the Gulf of Oman, saying it had collided with an Iranian vessel, losing two crew members and injuring others, while Washington demanded its immediate release.
The agency gave no further details, but several ships have been attacked in recent years off the coast of Yemen, which has been torn apart by an eight-year conflict between the Iran-aligned Houthi group and the Saudi-led military coalition backing Yemen's internationally recognized government.