WASHINGTON - United States and British warplanes, ships and submarines struck across Yemen overnight in retaliation against Houthi forces for attacks on Red Sea shipping, a widening of the regional conflict triggered by Israel’s war in Gaza.

Witnesses confirmed explosions throughout Yemen. They said raids targeted a military base adjacent to Sanaa airport, a military site near Taiz airport, a Houthi naval base in Hodeidah and military sites in Hajjah governorate.

“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,” US President Joe Biden said in a statement late on Jan 11.

The Houthis said five of their fighters had been killed in a total of 73 air strikes. They said they would retaliate for the strikes and continue their attacks, adding that all “interests” of the US and Britain are now “legitimate targets”.

A US official said more than a dozen locations were targeted in strikes that were not just symbolic but also intended to weaken the Houthis’ military capabilities.

“We were going after very specific capability in very specific locations with precision munitions,” the official said.

US Defence Secretary Lloyd Austin, who is in hospital due to surgery complications, said in a statement that the strikes targeted Houthi capabilities including drones, ballistic and cruise missiles, coastal radar and air surveillance.

The US said Australia, Bahrain, Canada and the Netherlands supported the operation.

Ms Kheloud, a resident of the capital Sanaa who gave just her first name, awoke to loud explosions from the direction of the airport to the north. “We saw a large fire from where the attack took place. It was half an hour of terror,” she said.

In a country only just emerging from nearly a decade of war that brought millions of people to the brink of famine, the morning of Jan 12 brought long queues at petrol stations from people fearing an extended new conflict with the West.

“There is a lot of worry that the fuel shortages will repeat themselves and food supplies will be scarce,” said Mr Ali Ahmad, 52. “We are rushing to fuel our car and we bought flour and rice in case of any emergency because we are expecting the Houthis to respond and an escalation to take place.”

In Yemen’s main Red Sea port Hodeidah, a resident who gave only his first name Mahmoud said troops were spreading through the streets and military vehicles were leaving barracks with security escorts.

Britain’s defence ministry said early indications were that “the Houthis’ ability to threaten merchant shipping has taken a blow”. Mr James Heappey, a junior defence minister, said no further action was planned for now.

The price of oil rose sharply on concern that supplies could be disrupted.

The Houthis are an armed movement that took control of most of Yemen over the past decade.

In December, the group said it would target all ships heading to Israel regardless of their nationality, and warned all international shipping companies against dealing with Israeli ports. It said its actions are a show of support for Palestinians and Hamas, the armed outfit that controls Gaza.

Around 12 per cent of the world’s seaborne trade passes through the Red Sea on routes between Europe and Asia.

The US and allies had deployed a naval task force to the area in December, and the situation had escalated in recent days. The US and British strikes took place outside that coalition.

US helicopters directly struck Houthi forces for the first time on Dec 31, sinking three boats and killing fighters attempting to board a ship.

On Jan 9, the US and Britain shot down 21 missiles and drones in what they described as the biggest Houthi attack yet, which they said had directly targeted their warships.

Iran condemned the US and British attacks. Other countries in the region, including Iraq, Oman and Turkey, issued similar condemnations. Ankara slammed the strikes as a disproportionate use of force and accused the US and Britain of trying to turn the Red Sea into a “sea of blood”.

Russia said the US and British move amounted to an irresponsible adventure that risked sowing chaos across the entire Middle East.

Elsewhere, Italy declined to take part in the strikes, a government source said on Jan 12, explaining that Rome preferred to pursue a “calming” policy in the Red Sea.

Reactions in the US were mixed.

Senate Republican Leader Mitch McConnell said he welcomed the US and coalition operations against the Houthis.

“President Biden’s decision to use military force against these Iranian proxies is overdue. I am hopeful these operations mark an enduring shift in the Biden administration’s approach to Iran and its proxies,” Mr McConnell added.

US Senator Roger Wicker said that it is time to dispense with the hollow talk of “joint resolutions” and “maritime task forces”.

“This strike should be a warning to the Houthis and other Iranian proxies that they will suffer catastrophic consequences from escalation in the region,” he said.

Others were critical. “The President needs to come to Congress before launching a strike against the Houthis in Yemen and involving us in another Middle East conflict. That is Article I of the Constitution. I will stand up for that regardless of whether a Democrat or Republican is in the White House,” said Representative Ro Khanna.

Representative Jason Crow said he would not support “us being pulled into a broader war”.

Representative Val Hoyle said: “These air strikes have not been authorised by Congress. The Constitution is clear: Congress has the sole authority to authorise military involvement in overseas conflicts. Every president must first come to Congress and ask for military authorisation, regardless of party.”

Representative Mark Pocan said the US cannot risk getting entangled into another decades-long conflict without congressional authorisation.

He added that the White House must work with Congress before continuing these air strikes in Yemen.

Fears of escalation

Houthi attacks on commercial ships have forced shipping lines to send vessels on a longer, costlier route around Africa. It created fears of a new bout of inflation and supply chain disruption derailing the global economic recovery.

Shipping company Maersk said on Jan 12 that it hopes international interventions and a larger naval presence in the Red Sea will eventually lead to maritime commerce resuming through the strait.

“We hope that these interventions and a larger naval presence will eventually lead to a lowered threat environment allowing maritime commerce to transit through the Red Sea and once again return to using the Suez Canal as a gateway,” Maersk said in an e-mailed statement.

Electric vehicle maker Tesla said on Jan 11 that it was shutting its factory in Germany for two weeks because of delays to parts supplies arriving from Asia as a result of Red Sea unrest, the first big manufacturer to make such an announcement.

The strikes were the first by the US on Yemeni territory since 2016, and the first time it has attacked the Houthis on any such scale.

“The concern is that this could escalate,” said Dr Andreas Krieg at King’s College in London, warning of the risk that Saudi Arabia and the United Arab Emirates could also be drawn into the confrontation.

Saudi Arabia called for restraint and “avoiding escalation”. The Saudis have backed the opposing side in a war against the Houthis for nearly a decade, which has lately been in a delicate state of UN-backed peace negotiations.

The US also accused Iran of being involved operationally in the Houthi attacks, providing the military capabilities and intelligence to carry them out.

“We believe that they have been certainly involved in every phase of this,” a senior US official told reporters.

Violence has escalated in Lebanon, the Israeli-occupied West Bank, Syria and Iraq in the three months since Israel mounted a military assault on Gaza.

The Palestinian authorities said Israel has killed more than 23,000 Palestinians during its operation to eradicate Hamas, whose fighters attacked Israel on Oct 7, killing 1,200 people and seizing 240 hostages.

The US has troops on the ground in Syria and Iraq, and has previously retaliated for attacks there by Iran-backed groups. Iraq’s state news agency quoted an adviser to its prime minister as saying the West was expanding the conflict. REUTERS