Iran’s Islamic Revolutionary Guard Corps fired at least two missiles at commercial vessels transiting the Strait of Hormuz early on Tuesday, two senior U.S. officials told Axios.

Both ships suffered significant damage, but no casualties were reported, one of the cited officials said.

U.K. Maritime Trade Operations (UKMTO) confirmed one of the incidents, saying a tanker “reported being hit by an unknown projectile on the port side causing a fire, whilst traveling southbound.”