LONDON, Aug. 24 (Xinhua) -- A tanker was struck by an unknown projectile 63 nautical miles west of the Red Sea port of Yanbu, Saudi Arabia, the United Kingdom Maritime Trade Operations (UKMTO) said on Monday.

All crew are safe and accounted for, and no environmental impact has been reported, said UKMTO.

Vessels are advised to transit with caution and report any suspicious activity to UKMTO.