Three vessels were struck by unknown projectiles in the Strait of Hormuz on Tuesday, the United Kingdom Maritime Trade Operations Centre said Wednesday.
UKMTO said a crude oil tanker and two other vessels were each hit by an unidentified projectile.
The agency had initially described one of the vessels as an LNG tanker before later referring to it more generally as a tanker.
The Strait of Hormuz has become a major flashpoint in the ongoing war between Iran and the U.S.
Before the conflict, around one-fifth of the world's oil and liquefied natural gas passed through the strategic waterway.
Since the war began, Iran has blocked commercial shipping through the strait and fired on vessels it accuses of crossing without authorization.
The U.S. has responded by imposing a counterblockade on Iranian ports aimed at preventing Tehran from exporting oil.