Iranian-backed Houthi militants claimed on Monday that they had launched one of their most damaging attacks yet on a ship, saying that a strike put a British cargo ship at risk of sinking.

U.S. Central Command said that two anti-ship ballistic missiles were launched from Houthi-controlled areas in Yemen toward a Belize-flagged, British-owned ship, the MV Rubymar, in the Gulf of Aden on Sunday, but that only one missile struck the ship. Heeding the ship’s distress signals, a merchant vessel and a coalition warship assisted the crew members, who abandoned ship and were safely transported to a nearby port, Centcom added.

Houthi military spokesman Yahya Saree on Monday said “the ship was severely damaged, leading to its complete halt. … It is now at risk of sinking in the Gulf Aden.”

The Washington Post could not independently verify that claim.

United Kingdom Maritime Trade Operations on Sunday said it received a report of an attack 35 nautical miles (40 miles) south of Mukha, Yemen. “Crew have abandoned vessel. Vessel at anchor and all crew are safe,” it said in an update posted on social media.

In his statement, Saree said that in the past 24 hours, the Houthis had also targeted two American ships in the Gulf of Aden, the Sea Champion and the Navis Fortuna.

The Houthis have been attacking commercial and naval vessels traversing the Red Sea since November in protest of Israel’s military campaign in the Gaza Strip.

Last month, the United States launched a military campaign targeting the Houthis and their infrastructure, but attempts to deter the rebels’ attacks on maritime commerce have not succeeded. Saree on Monday said the group would halt their attacks when “the siege on the Palestinian people in the Gaza Strip is lifted.”