US and UK forces hit 18 Houthi targets including underground weapons and missile storage facilities, officials say.

In a joint statement on Saturday, the US and UK said the military action against 18 Houthi targets in Yemen included attacks on underground weapons and missile storage facilities, air defence systems, radars and a helicopter.

The operation marked the fourth time that the US and UK militaries have carried out joint attacks against the Houthis since January 12.

The US has also been carrying out almost daily raids to take out Houthi targets, including incoming missiles, rockets and drones targeting commercial and other Navy vessels. The raids, however, have so far failed to halt the Houthis’ attacks, which have upset global trade and raised shipping rates.

US Defence Secretary Lloyd Austin said the latest strikes were meant “to further disrupt and degrade the capabilities of the Iranian-backed Houthi militia”.

“We will continue to make clear to the Houthis that they will bear the consequences if they do not stop their illegal attacks, which harm Middle Eastern economies, cause environmental damage and disrupt the delivery of humanitarian aid to Yemen and other countries,” Austin said.

The attacks were supported by Australia, Bahrain, Canada, Denmark, the Netherlands and New Zealand.

The Houthis denounced the “US-British aggression” and pledged to keep up its military operations.

“The Yemeni Armed Forces affirm that they will confront the US-British escalation with more qualitative military operations against all hostile targets in the Red and Arabian Seas in defense of our country, our people and our nation,” the group said in a statement.

The Houthis have launched at least 57 attacks on commercial and military ships in the Red Sea and the Gulf of Aden since November 19, and the pace has picked up in recent days.

A spokesman for the Houthis claimed an attack on MV Torm Thor, a US-flagged, owned and operated chemical and oil tanker, on Saturday, saying the group targeted the vessel using a “number of appropriate naval missiles”.

The US Central Command confirmed the attack, saying its forces downed an antiship ballistic missile launched from Houthi-held areas in Yemen towards the Gulf of Aden, adding that the missile was likely targeting MV Torm Thor.

The tanker was not damaged and there were no injuries, it said.

Earlier this week, the Houthis also claimed responsibility for an attack on a UK-owned cargo ship and a drone assault on a US destroyer, and said they targeted Israel’s port and resort city of Eilat with ballistic missiles and drones.

No ships have been sunk nor crew killed during the Houthi campaign.

However, there are concerns about the fate of the UK-registered Rubymar cargo vessel, which was struck on February 18 and its crew evacuated. The US military has said the Rubymar was carrying more than 41,000 tonnes of fertiliser when it was hit, which could spill into the Red Sea and cause an environmental disaster.

The turmoil from Israel’s war on Gaza has also spilled over to into other parts of the Middle East.

Apart from the Houthi attacks on vital shipping lanes, Lebanon’s Iran-backed Hezbollah group has traded fire with Israel along the Israel-Lebanon border and pro-Iran Iraqi militia have attacked bases that host US forces.