The US and Britain attacked Houthi positions in Yemen (UPDATED)

The United States and Britain launched air and naval strikes on Houthi military targets in Yemen in response to the movement's attacks on ships in the Red Sea, a dramatic regional expansion of the war between Israel and Hamas in Gaza.

As witnesses in Yemen confirmed to the media about explosions across the country, President Joe Biden warned in a statement late last night that he would not hesitate to take further action if necessary.

"These targeted strikes send a clear message that the United States and our partners will not tolerate attacks on our personnel or allow hostile actors to threaten freedom of navigation," Biden said.

A statement from Britain's Ministry of Defense said "initial indications are that the Houthis' ability to threaten merchant shipping has suffered a blow".

US Defense Secretary Lloyd Austin, who is in hospital due to complications from surgery, said the strikes targeted Houthi capabilities, including drones, ballistic and cruise missiles, coastal radars and aerial surveillance.

A Houthi representative confirmed the "raids" in the capital Sana'a, along with the cities of Saada and Dhammar, as well as in Hodeidah province, calling them "American-Zionist-British aggression".

Witnesses told CNN that the raids targeted a military base near Sana'a airport, a military site near Taiz airport, a Houthi naval base in Hodeida and military sites in Hajjah province.

The ongoing strikes are one of the most dramatic demonstrations yet of the escalating war between Israel and Hamas in the Middle East since it broke out in October, although the US has said it has no intention of escalating tensions.

One US official, speaking on condition of anonymity, said the strikes were carried out by aircraft, ships and submarines. The official said more than a dozen locations were targeted and that they were aimed at weakening the Houthis' military capacity and were not merely symbolic.

"The goal of these strikes was very clear from the beginning and from the president, and that was to eliminate the ability of the Houthis to attack maritime vessels, whether commercial or military," another senior US military official said.

The Houthis, who control most of Yemen, have defied calls from the United Nations and other international organizations to end their missile and drone attacks on Red Sea shipping lanes, as well as warnings from the United States about the consequences if they don't they do it.

The Houthis say their attacks are in support of Hamas, the Palestinian Islamist group that controls Gaza. Israel launched a military offensive that killed more than 23,000 Palestinians in Gaza following a Hamas attack on Israel on October 7 that killed 1,200 and kidnapped 240.

The Houthis have attacked 27 ships since late December, disrupting international trade on the key route between Europe and Asia, which carries about 15 percent of the world's maritime traffic.

The overnight strikes in Yemen came just days after the Houthis' largest attack to date on January 9 in the Red Sea, which forced US and British navies to shoot down 21 Houthi drones and missiles fired into the southern Red Sea. The US military described it as a complex attack.

In his statement, Biden said the Houthis had directly targeted American ships.

Prominent Republicans in Congress welcomed the move but called it late, while some of Biden's Democrats expressed concern that the US could be embroiled in another decades-long war.

In December, more than 20 countries agreed to take part in the US-led coalition known as Operation Prosperity Guardian, which guards commercial traffic in the Red Sea. However, US and UK strikes are conducted outside this protective coalition.

Biden said Australia, Bahrain, Canada and the Netherlands supported the operation.

"The international community's response to these reckless attacks was united and decisive," Biden said.

US and British airstrikes launched early on January 12 against Houthi targets in Yemen over recent attacks on ships in the Red Sea were "necessary and proportionate", UK Prime Minister Rishi Sunak said.

"Despite repeated warnings from the international community, the Houthis continued to carry out attacks in the Red Sea," Sunak said.

"That is why we have taken limited, necessary and proportionate self-defense action, together with the United States ... to degrade the Houthis' military capabilities and protect global shipping," he added.

"Our goal remains to de-escalate tensions and restore stability in the Red Sea, but let our message be clear: we will not hesitate to protect lives and safeguard the free flow of trade in one of the world's most important waterways in the face of continuing threats," said a joint statement by the governments of Australia, Bahrain, Canada, Denmark, Germany, the Netherlands, New Zealand, South Korea, the United Kingdom and the United States.

At the same time, Saudi Arabia said it was following with "great concern" US and British airstrikes in neighboring Yemen, the foreign ministry said in a Jan. 12 statement, calling for a military escalation.

"The Kingdom of Saudi Arabia is following with great concern the military operations taking place in the Red Sea region and the airstrikes on a number of sites in the Republic of Yemen," the statement said, calling for "restraint and avoidance of military escalation." /BGNES