The extent of the damage and possible casualties wasn't immediately clear, though the number of strikes appeared particularly intense.
Suspected US airstrikes hit sites across Yemen controlled by the Houthi rebels early on Friday, including neighbourhoods in the capital, Sanaa.
Although the extent of the damage and possible casualties was not immediately clear, the number of strikes and strike sites appeared particularly intense compared to other days in US campaign that began on 15 March.
Initial reports from the Houthis described at least seven people being injured in the latest attacks in the capital.
Other strikes hit around the Red Sea port city of Hodeida, the rebel stronghold of Saada, and in Yemen’s al-Jawf, Amran, and Marib provinces.
The Houthis did not immediately acknowledge what had been targeted at those sites, other than Sanaa International Airport, which is used for both civilian and military traffic.
Other areas hit included mountainous terrain north of Sanaa in Amran, where military camps and other installations are believed to be located.
The Houthis' al-Masirah satellite news network said communication networks were down after the attacks, which included at least 19 strikes there alone.
No confirmation from US military
The US military's Central Command, which now has authority from the White House to strike offensively in Yemen without pre-approval, did not immediately acknowledge conducting any strikes.
The command, which under Biden offered details on individual strikes, has not provided that information in this campaign.
The new campaign of airstrikes — which the Houthis say have killed at least 57 people — started after the rebels threatened to begin targeting what they define as “Israeli” ships.
The rebels in the past have had a loose definition of what constitutes an Israeli ship, meaning other vessels could be targeted as well.
The group have said their attacks are a response to Israel blocking aid into the Gaza Strip.
The Houthis had targeted over 100 merchant vessels with missiles and drones, sinking two vessels and killing four sailors during their campaign targeting ships from November 2023 until January of this year.
They have also launched attacks targeting American warships, though none have been hit so far.
The attacks greatly raised the Houthis’ profile as they faced economic problems and launched a crackdown targeting any dissent and aid workers at home amid Yemen’s decade-long war that has torn apart the Arab world’s poorest nation.