Witnesses confirmed explosions at military bases near airports in the capital Sanaa and Yemen's third city Taiz, a naval base at Yemen's main Red Sea port Hodeidah and military sites in the coastal 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.
White House spokesman John Kirby said the strikes had targeted the Houthis' ability to store, launch and guide missiles or drones, and that their impact was being assessed.
"We're not interested in ... a war with Yemen," he told reporters.
Yemen's Houthis top leader Abdul-Malik Al-Houthi warned no US aggression would go unanswered. (EPA PHOTO)
The Houthis, who have controlled most of Yemen for nearly a decade, said five fighters had been killed in a total of 73 air strikes. They vowed to retaliate and continue their attacks on shipping, which they say are intended to support Palestinians against Israel.
The UK Maritime Trade Operations information hub said it had received reports of a missile landing in the sea around 500m from a ship about 90 nautical miles southeast of the Yemeni port of Aden. Three small boats were also reported to have neared.
The shipping security firm Ambrey identified it as a Panama-flagged tanker carrying Russian oil.
In Yemen, crowds gathered in cities. Drone footage on the Houthis' al-Masirah TV showed hundreds of thousands of people in Sanaa chanting slogans denouncing Israel and the United States.
"Your strikes on Yemen are terrorism," said Mohammed Ali al-Houthi, member of the Houthi Supreme Political Council.Â
"The United States is the Devil."
The US military said 60 targets had been hit using more than 100 precision-guided munition.The commander of US air operations in the Middle East, Air Force Lieutenant-General Alex Grynkewich, said 60 targets at 16 locations had been hit using more than 100 precision-guided munitions.
A US official said the targets had been chosen to weaken the Houthis' ability to attack: "We were going after very specific capability in very specific locations with precision munitions."
US and UK militaries bombed more than a dozen sites used by the Iranian-backed Houthis in Yemen. (AP PHOTO)
The United States and some allies sent a naval task force in December, and recent days saw increasing escalation. US helicopters sank three Houthi boats on New Year's Eve, killing fighters attempting to board a ship. On Tuesday, the United States and Britain shot down 21 missiles and drones.
However, not all major US allies chose to back the strikes.
The Netherlands, Australia, Canada and Bahrain provided logistical and intelligence support, while Germany, Denmark, New Zealand and South Korea signed a joint statement defending the attacks and warning of further action.
But Italy, Spain and France chose not to sign or participate, fearing a wider escalation.
Egypt, which controls the Suez Canal linking the Red Sea to the Mediterranean, expressed deep concern at the attack on the Houthis.
Iran-backed groups have increased attacks on US targets in several countries since Hamas militants attacked Israel on October 7, killing 1,200 people and precipitating the war in Gaza, which has so far killed more than 23,000.
Within hours of the air strikes, the US Treasury Department issued sanctions targeting four oil tankers and two firms whose shipments it said were helping to finance the Houthis and Iran's Quds Force.
Houthi attacks have forced commercial ships to take a longer, costlier route around Africa, creating fears of a new bout of inflation and supply chain disruption. Container shipping rates for key global routes have soared this week.
