Projectiles struck a ship in the narrow Strait of Hormuz, the British military said on Monday.
It marked the second attack in hours as tensions remain high between Iran and the United States.
The British military’s United Kingdom Maritime Trade Operations centre issued the alert, saying a tanker had been targeted off Fujairah, United Arab Emirates, in the strait around 11.40pm on Sunday.
It described the tanker had been struck by “unknown projectiles”.
“All crew reported safe,” the centre said. “No environmental impact reported.”
Another ship came under attack in the strait on Sunday.
