The Saudi-led coalition in Yemen said it destroyed an explosive-laden boat, causing damage to a nearby oil tanker on Wednesday.
Earlier, the operator of the tanker Agrari said it was damaged by an "unknown source" at Saudi Arabia's Red Sea Shuqaiq port.
The coalition said the vessel sustained minor damage from shrapnel from the exploding boat being used in an attempted attack by Yemen's Iran-backed Houthi rebels, Saudi state TV channel El Ekbariya reported.
Greek operator TMS Tankers said the ship was preparing to depart after offloading the oil it was carrying when it was struck.
"The Agrari was struck about one metre above the waterline and has suffered a breach," it said.
The company said there were no casualties and no pollution reported.
"The vessel is in ballast condition and stable," it said.
The incident was also confirmed by British intelligence firm Ambrey, which said a tanker was attacked off Shuqaiq in Jizan province, which borders Yemen.
A Saudi Aramco spokesman said the incident had nothing to do with the company and the terminal and associated infrastructure were not owned or operated by the state-backed firm.
Attacks by the Houthis on ships have been increasing.
A Saudi-led coalition is supporting the internationally recognised government in Yemen.
The coalition reported on Tuesday that it removed and destroyed five Iranian-made naval mines planted by the Houthis in the southern Red Sea, condemning the attempted attacks as “a serious threat to maritime security in Bab Al Mandeb".
On Monday, a missile fired by the rebels struck an Aramco oil depot in Jeddah, Saudi Arabia.
After the attack on Wednesday, the Agrari was boarded by local authorities, including the coastguard, and an investigation has begun.
TMS said Agrari was an Aframax tanker that sailed under a Maltese flag.
The 107,009 deadweight tonnage vessel is mainly used for the transport of crude and products.
Agrari, which was built in 2009 by Shanghai Waigaoqiao Shipbuilding, carried crude from Latvia to Shuqaiq on Monday, energy intelligence firm Vortexa said.
The latest incident echoes a spate of attacks on tankers transiting the Strait of Hormuz, to the east of the Arabian Peninsula last year.
In May 2019, four tankers off the coast of Fujairah were attacked in what authorities said appeared to be sabotage.
A couple of months later, Iran's Islamic Revolutionary Guard Corps captured the British-flagged Stena Impero as it was en route to the port city of Jubail in Saudi Arabia.