A Liberia-flagged cargo ship was struck by an unknown projectile Tuesday while transiting the strategically vital Strait of Hormuz near the coast of Oman, forcing the crew to abandon the vessel as rescuers searched for a missing crew member.

The dry bulk carrier Minoan Pioneer was hit in its engine room, maritime security sources told Reuters.

British maritime risk management firm Vanguard separately told the outlet that the impact sparked a fire in the ship's accommodation area.

“The crew are fighting the fire and require assistance, while the third engineer is reported missing," it said.

A salvage operation is underway, with a tugboat equipped for firefighting dispatched to the scene, one maritime security source said. Most of the crew evacuated into a lifeboat and are reported to be safe, according to the outlet.

It was the fourth attack on a vessel in the waterway since Friday as tensions remain high in the Strait of Hormuz, one of the world's most important maritime chokepoints.

President Donald Trump had vowed last month “to bomb and destroy” one Iranian bridge or power plant each time Iran shoots at a ship in the Strait of Hormuz.

Meanwhile, Iran has halted most traffic through the Strait of Hormuz while the U.S. maintains a blockade of Iranian shipping and ports, disrupting a waterway that typically carries roughly one-fifth of global oil and liquefied natural gas shipments.