The United States and Britain launched strikes against sites linked to the Houthi movement in Yemen, the first on the country since the Iran-backed group started targeting international shipping in the Red Sea late last year.

As witnesses in Yemen confirmed explosions throughout the country to Reuters, President Joe Biden cautioned in a statement late on Thursday he would not hesitate to carry out further action if needed.

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

Britain's ministry of defense said in a statement that "early indications are that the Houthis' ability to threaten merchant shipping has taken a blow."

A Houthi official confirmed "raids" in the capital Sanaa along with the cities of Saada and Dhamar as well as in Hodeidah governorate, calling them "American-Zionist-British aggression."

The ongoing strikes are one of the most dramatic demonstrations to date of the widening of Israel-Hamas war in the Middle East since its eruption in October.

One U.S. official, speaking on condition of anonymity, said the strikes were being carried out by aircraft, ship and submarine. The official said more than a dozen locations were targeted and the strikes were intended to weaken the Houthi's military capabilities and were not just symbolic.

(With inputs from agencies)