Yemen’s Houthi militants are “believed to have sunk” a second ship in the Red Sea, the United Kingdom Maritime Trade Operations (UKMTO) said on Tuesday.

The Houthis and other sources previously identified the damaged ship as the Greek-owned Tutor. It was struck by missiles and an explosive-laden remote-controlled boat on June 12 and had been taking on water. One crew member from the Tutor remains missing.

The Tutor’s manager could not be immediately reached for comment.

The sinking of the Tutor would mark the second downing of a commercial vessel targeted by the Houthis since November, in what they say is in solidarity with Palestinians in Gaza.

The UK-owned Rubymar sank in the Red Sea on March 2, about two week after it was damaged by a Houthi attack.

The Houthis also have seized another vessel and killed three sailors in separate attacks.

The Iran-back militants’ drone and missile assaults have forced shipping firms to divert ships to the longer route around southern Africa, disrupting global trade by delaying deliveries and sending costs higher.