A second tanker attack in the same area off Saudi Arabia was reported on Saturday, the UK Maritime Trade Operations (UKMTO) said, according to Anadolu Agency.
The latest incident occurred at 19:22 GMT on Friday, about 78 nautical miles (144 kilometres) northeast of Al Jubayl, UKMTO said in an advisory.
The tanker’s master reported that a rocket-propelled grenade fired from a small boat struck the vessel, damaging its aft port quarter.
All crew members were accounted for and reported safe. A full assessment of the damage and any environmental impact was not immediately available.
Authorities are investigating the incident. Vessels in the area were advised to proceed with caution and report any suspicious activity.
Earlier on Saturday, UKMTO reported that another tanker had been struck by an unknown projectile on Friday, about 68 nautical miles (126 kilometres) northeast of Al Jubayl.
All crew members were safely evacuated in that incident, and no environmental impact was reported.