Muscat: A Malta-flagged container ship was struck off the coast of Oman on Wednesday while transiting the Strait of Hormuz, two maritime security agencies have reported, as Iran stepped up its retaliatory campaign in the Gulf.

The vessel, identified by private maritime security firm Vanguard Tech as the Safeen Prestige, was two nautical miles north of Oman and travelling eastbound through the strait when it was “hit by an unknown projectile just above the water line, causing a fire in the engine room,” according to the United Kingdom Maritime Trade Operations (UKMTO).

Shipping tracker Marine Traffic reported the ship had been en route from Ghantoot port in the United Arab Emirates to Jeddah in Saudi Arabia.

It was the fourth incident in the region within 24 hours, following strikes or near-misses affecting three other vessels off the coasts of the UAE and Oman.

Iran’s Revolutionary Guards said on Wednesday that they had “complete control” over the strategic waterway, through which around 20 percent of global seaborne oil passes, warning that any ships attempting to transit risked damage from missiles or stray drones.

With energy prices already surging, US President Donald Trump said the US Navy was prepared to escort oil tankers through the vital shipping route.