Yemen's Houthi movement said on Sunday it was ready to "meet escalation with escalation" after US strikes targeting the Iran-aligned group over its threat to resume Red Sea shipping attacks triggered a diplomatic backlash from Moscow and Tehran.
The strikes - which killed at least 31 people at the start of a campaign that one US official told Reuters might continue for weeks - are the biggest US military operation in the Middle East since President Donald Trump took office in January.
The Houthis' political bureau described the attacks as a "war crime".
"Our Yemeni armed forces are fully prepared to respond to escalation with escalation," it said in a statement.
Trump also warned Iran, the Houthis' main backer, that it needed to end support for the group immediately. He said if Iran threatened the United States, "America will hold you fully accountable and, we won't be nice about it!"
In response, the top commander of Iran's Revolutionary Guards said the Houthis took their own strategic and operational decisions and Tehran would react decisively to any action against it.
"We warn our enemies that Iran will respond decisively and destructively if they take their threats into action," Hossein Salami told state media.
Russian Foreign Minister Sergei Lavrov called US Secretary of State Marco Rubio to urge an "immediate cessation of the use of force and the importance for all sides to engage in political dialogue," Russia's foreign ministry said on Sunday.
Lavrov's call to halt the strikes came as Trump has been pressing Moscow to sign a US proposal for a 30-day ceasefire between Russia and Ukraine, which Ukraine accepted last week, but Russia has said needs to be reworked.
Trump is also trying to bring Tehran to the negotiating table over its nuclear programme, while also ramping up sanctions pressure.
'LIKE AN EARTHQUAKE'
Most of the 31 people confirmed killed in the US strikes were women and children, Anees al-Asbahi, spokesperson for the Houthi-run health ministry said in an updated toll on Sunday. More than 100 were injured, he said.
Residents in Sanaa said the strikes hit a neighbourhood known to host several members of the Houthi leadership.
"The explosions were violent and shook the neighbourhood like an earthquake. They terrified our women and children," one of the residents, who gave his name as Abdullah Yahia, told Reuters.
In Sanaa, a crane and bulldozer were used to remove debris at one site and people used their bare hands to pick through the rubble. At a hospital, medics treated the injured, including children, and the bodies of several casualties, wrapped in plastic sheets, were placed in a yard, Reuters footage showed.
Strikes also targeted Houthi military sites in Yemen's southwestern city of Taiz, two witnesses said on Sunday.
Another strike on a power station in the town of Dahyan in Saada led to a power cut, Al-Masirah TV reported early on Sunday. Dahyan is where Abdul Malik al-Houthi, the enigmatic leader of the Houthis, often meets visitors.
RED SEA ATTACKS
The Houthis, an armed movement that took control of most of Yemen over the past decade, said last week they would resume attacks on Israeli ships passing through Red Sea shipping lanes off Yemen if Israel did not lift a block on aid into Gaza.
The Houthis had launched scores of attacks targeting shipping from November 2023, saying they were in solidarity with Palestinians over Israel's war with Hamas in Gaza.
The attacks disrupted global commerce and set the U.S. military off on a costly campaign to intercept missiles and drones that have burned through stocks of U.S. air defences.
The group has not launched new strikes on Red Sea shipping since it halted attacks when Israel and Hamas agreed to a ceasefire in Gaza in January.
But on March 12, the Houthis' military spokesperson said the Houthi threat to attack Israeli ships would remain in effect until Israel resumed the delivery of aid and food into Gaza.
The previous US administration of then-President Joe Biden had sought to degrade the Houthis' ability to attack vessels off its coast but limited the U.S. actions.
US officials, speaking on condition of anonymity, say Trump has authorized a more aggressive approach.
"To all Houthi terrorists, YOUR TIME IS UP, AND YOUR ATTACKS MUST STOP, STARTING TODAY. IF THEY DON’T, HELL WILL RAIN DOWN UPON YOU LIKE NOTHING YOU HAVE EVER SEEN BEFORE!" Trump posted late Saturday on his Truth Social platform.
STRIKES ACROSS YEMEN
The US military's Central Command, which oversees troops in the Middle East, described Saturday's strikes as the start of a large-scale operation across Yemen.
The strikes were carried out in part by fighter aircraft from the Harry S. Truman aircraft carrier, which is in the Red Sea, officials said.
"Houthi attacks on American ships & aircraft (and our troops!) will not be tolerated; and Iran, their benefactor, is on notice," Defense Secretary Pete Hegseth wrote on X.
Iran's foreign ministry condemned strikes on Yemen as a "gross violation of the principles of the United Nations Charter and the fundamental rules of international law".
The Iranian Foreign Minister Abbas Araqchi said the U.S. government had "no authority, or business, dictating Iranian foreign policy."
The Lebanese armed group Hezbollah, also backed by Iran, expressed solidarity with the Houthis on Sunday: "This barbaric aggression constitutes a war crime and a flagrant violation of international law and norms," a statement by the group said.