Iran's Revolutionary Guards fired at least two missiles at commercial ships transiting through the Strait of Hormuz on Monday night, Axios reported, citing two U.S. officials.
Two commercial ships suffered significant damage but had no casualties, the report said, citing a U.S. official.
U.S. Central Command did not immediately respond to Reuters' request for comment.
The United Kingdom Maritime Trade Operations agency (UKMTO) said early on Tuesday that a tanker was hit by an unknown projectile on its port side while traveling southbound about 8 nautical miles (15 km) east of Oman's Limah, causing a fire; no casualties or environmental impact had been reported.
The development comes after indirect U.S.-Iran talks ended last week without any public sign of headway toward a lasting peace, despite a 60-day ceasefire intended to create space for diplomacy following the U.S. and Israeli strikes that triggered the conflict.
President Donald Trump said on Monday the United States would either reach a deal with Iran or "finish the job," renewing his threat of military action as Tehran projects defiance following the funeral of former Supreme Leader Ayatollah Ali Khamenei.
"Our missiles and drones are ready to fire at you," Iran's Revolutionary Guard warned ships via maritime radio over the weekend, the Wall Street Journal reported on Monday, quoting from a recording it obtained.
One of the vessels under attack appears to be Al Rekayyat, a liquefied natural gas tanker owned and managed by Nakilat, the shipping arm of Qatar's LNG industry, the WSJ said, adding that the ship had been hit on the port side, at the top of the engine room.
"Engine room fire and full of smoke. Unable to assess further damage. All crew are safe and mustered on the starboard side," WSJ quoted from a recording.
The vessel was at the mouth of the strait, in the Gulf of Oman, when it was attacked, the WSJ said.
Investors have been keeping a close eye on talks between the U.S. and Iran over the fate of shipping through the Strait of Hormuz while tracking the recovery in Gulf oil exports.
