The United Kingdom Maritime Trade Operations (UKMTO) says an oil tanker was struck by an unidentified projectile in the Strait of Hormuz on Tuesday.
In a statement issued on Thursday, UKMTO said the incident, which occurred off the Omani coast, caused a fire on the vessel.
UKMTO said the fire had since been extinguished and that all crew members were safe and accounted for, with no environmental impact reported.
The agency said investigations are ongoing and advised vessels to transit with caution and report suspicious activities.
The UKMTO report comes a day after US President Donald Trump said the Strait of Hormuz has been fully cleared of mines and described it as “a functioning strait”.
The US military has maintained a naval blockade against Iranian ships at the vital checkpoint and used the southern Omani lane to escort oil tankers in and out of the Gulf.
Traffic through the Strait of Hormuz has reportedly declined this week and remains far below pre-war levels, despite US efforts to help escort vessels.
Meanwhile, Iran and Oman, which both border Hormuz, have agreed on a temporary maritime corridor intended to restore safer passage through the strait.
Trump has threatened to bomb Oman if it “gets in the way” of his administration’s talks with Iran to reopen Hormuz.
Kazem Gharibabadi, Iran’s deputy foreign minister, had said the waterway would not fully reopen until the US fulfils its commitments, including lifting the naval blockade, under an interim peace deal framework signed in June that has since lapsed.