An Iranian-owned oil tanker has been struck by two missiles off the Saudi port of Jeddah, Iranian state media reported, quoting the National Iranian Oil Company, which owns the vessel.
The tanker was set ablaze and suffered heavy damage and was leaking crude about 100km from Jeddah, according to Iranian media.
The alleged attack is the latest incident involving oil tankers in the Red Sea and Gulf region, and is likely to ratchet up tension between Iran and Saudi Arabia.
The US Navy's Fifth Fleet, which operates in the region, said it was aware of media reports about the tanker, but did not have any further information at this time.
There was no immediate comment from Saudi Arabia.
Iran's ISNA news agency cited a source saying the vessel was struck in a "terrorist" attack. Iran's state television reported that two of its tanks were damaged.
Tension is already high in the Red Sea shipping area, which links the Indian Ocean with the Mediterranean via the Suez Canal.
It follows strikes on key Saudi oil installations in September and attacks on tankers in the Gulf area in May and June.
The United States has blamed Iran, which denied any role.
#UPDATE Suspected missile strikes have hit an Iranian oil tanker near the Saudi coast, company says.— AFP news agency (@AFP) October 11, 2019
It is the first Iranian vessel targeted since a spate of attacks in the Gulf Washington blamed on Tehranhttps://t.co/uGqCl7bt1N pic.twitter.com/WAOc8sDPZz
Oil prices jumped 2% after reports of the tanker explosion, with benchmark Brent and US West Texas Intermediate crude futures rising more than $1 a barrel.
A NIOC statement, carried by Iranian media, identified the ship as Sabiti, a Suez max vessel, after initial reports had identified it as the Sinopa, another Suez max ship.
Refinitiv ship tracking data gave the Sabiti's last reported position on 14 August as off the southern coast of Iran in the Gulf.
It said the Sinopa was in the Red Sea, according the latest data updated on 10 October.
Iran's Nour news agency, which is close to the Iranian Revolutionary Guard Corps, said the crew was safe.
The 14 September attacks on Saudi oil sites in the east of the kingdom shut down 5.7 million barrels per day (bpd) of production, about half of Saudi output and roughly 5% of global supply. Output has since been restored.
Yemen's Iran-aligned Houthi group claimed responsibility for those attacks, but a US official said they originated from southwestern Iran. Riyadh blamed Tehran. Iran denied any role.