A British maritime agency said on Wednesday that unknown projectiles struck three ships in the Strait of Hormuz the previous day.
A crude oil tanker and two other vessels had each "been struck by an unknown projectile", the United Kingdom Maritime Trade Operations Centre (UKMTO) said.
It had earlier described one of the vessels as an LNG tanker, before later describing it as a tanker.
The Strait of Hormuz is currently at the centre of the Middle East war between Iran and the United States.
Around a fifth of the world's oil and liquefied natural gas passed through the strategic shipping lane before the war.
But since the conflict broke out, Tehran has been blocking the passage of commercial ships, firing on vessels it accuses of unauthorised crossings.
Washington has responded with a counterblockade of Iranian ports in an effort to prevent Tehran from exporting its oil.
