The blast hit the MT Agrari, a Maltese-flagged, Greek-managed vessel off the coast of Shuqaiq, al-Jazeera reported.
A statement from the Agrari’s operators, quoted by The Associated Press news agency, said the tanker “was attacked by an unknown source.”
“The Agrari was struck about 1 meter above the waterline and has suffered a breach. It has been confirmed that the crew are safe and there have been no injuries.”
The ship was still floating off the coast and had been boarded by Saudi officials, the company said. Saudi Arabia did not immediately acknowledge the incident.
Ambrey, a British security firm, reported the blast and attributed it to a mine.