The U.S. military said Sunday it had struck more devices and missiles in Houthi-controlled areas of Yemen that were prepared to launch against ships in the Red Sea.

The strikes occurred Saturday between 4-5 p.m. (1300-1400 GMT) north of the city of Hodeida, the U.S. Central Command (CENTCOM) said on social media.

American “forces successfully conducted self-defense strikes against two unmanned surface vessels (USV) and three mobile anti-ship cruise missiles (ASCM)… that were prepared to launch against ships in the Red Sea,” the statement said.

The Houthi-run Al-Masirah television on Saturday night reported three strikes on the Salif port area, while an AFP correspondent in the area heard loud blasts.

The strikes are part of a series of actions taken by the United States and its allies against the Houthis, aimed at halting the Iran-backed rebels’ repeated attacks on vital Red Sea shipping lanes.

On Saturday, the Houthis confirmed that 17 of their fighters had been killed in recent strikes, following a previous announcement Thursday by the United States that it had struck missile launchers.

The Houthis, who control much of war-torn Yemen including the port of Hodeida, began their attacks in November, saying they were hitting Israel-linked vessels in support of Palestinians in Gaza, which has been ravaged by the Israel-Hamas war.

U.S. and British forces have responded with strikes against the Houthis, who have since declared the two countries’ interests to be legitimate targets as well.

On Tuesday the Houthi rebels said they had struck U.S. and British ships in two attacks in the Red Sea, causing minor damage but no casualties.

The Red Sea attacks have raised insurance premiums for shipping companies, forcing many to avoid the Red Sea, a vital route that normally carries about 12 percent of global maritime trade.