American and British naval ships, submarines and warplanes struck an airbase, airport and military camp in Yemen Friday to stop Houthi rebels from attacking Israel-bound ships in the Red Sea with bomb drones and missiles.

United States President Joe Biden called the airstrikes a “defensive action” to prevent Red Sea attacks and said he “will not hesitate” to order further military action if needed.

“Today, at my direction, US military forces — together with the United Kingdom and with support from Australia, Bahrain, Canada, and the Netherlands — successfully conducted strikes against a number of targets in Yemen used by Houthi rebels to endanger freedom of navigation in one of the world’s most vital waterways,” Biden said in a statement.

Biden called the strikes a “direct response” to the “unprecedented” attacks by the Houthis, “including the use of anti-ship ballistic missiles for the first time in history.”

“These attacks have endangered US personnel, civilian mariners, and our partners, jeopardized trade, and threatened freedom of navigation,” he said.

Houthi Deputy Foreign Minister Hussein Al-Ezzi said, “America and Britain will have to prepare to pay a heavy price and bear all the dire consequences of this blatant aggression.”

“The raids led to the death of five martyrs and the injury of six others from our armed forces,” Houthi military spokesperson Yahya Saree wrote on X.

Blaming the Houthis for ignoring “repeated warnings,” British Prime Minister Rishi Sunak said in a statement the strikes were “necessary and proportionate.”

The Houthis’ Al-Masirah TV station reported the airstrike with Agence France-Presse correspondents and witnesses also reporting they could hear bombardments.

The strikes involved fighter jets and Tomahawk missiles, the US Air Forces Central Command said in a statement. Sixty targets at 16 Houthi locations were hit by more than 100 precision-guided munitions, it said.

Unverified images on social media, some of them purportedly of Al-Dailami airbase north of Sanaa, showed explosions lighting up the sky as loud bangs and the roar of planes sounded.

US Defense Secretary Lloyd Austin said the strikes had “targeted sites associated with the Houthis’ unmanned aerial vehicle, ballistic and cruise missile, and coastal radar and air surveillance capabilities.”

A joint statement by the United States, Britain, Australia, Bahrain, Canada, Denmark, Germany, the Netherlands, New Zealand and South Korea said the “aim remains to de-escalate tensions and restore stability in the Red Sea.”

“But let our message be clear: We will not hesitate to defend lives and protect the free flow of commerce in one of the world’s most critical waterways in the face of continued threats,” it said.

The Houthi rebels say they are acting in solidarity with Palestinians in response to Israel’s bombardment of Gaza after the 7 October attack, and have also launched a series of drones and missiles towards Israel.