U.S. and British warplanes, ships and submarines launched dozens of air strikes across Yemen overnight in retaliation against Houthi forces for months of attacks on Red Sea shipping that the Iran-backed fighters cast as a response to the war in Gaza.

The Houthis, who have controlled most of Yemen for nearly a decade, said five fighters had been killed in a total of 73 air strikes. They vowed to retaliate and continue their attacks on shipping, which they say are intended to support Palestinians against Israel.

Iran-backed groups have increased attacks on U.S. targets in several countries since Hamas militants attacked Israel on Oct. 7, killing 1,200 people and precipitating the war in Gaza, which has so far killed more than 23,000.