The coalition said the strikes targeted a Houthi drone-manufacturing plant and a warehouse containing launch pads. Residents said a house was also hit, but no casualties were reported.

Saudi Arabia leads a Western-backed alliance of Yemeni and Arab forces that has been fighting the Iran-aligned Houthi movement in neighboring Yemen since March 2015, after Houthi forces drove Yemeni President Abd-Rabbu Mansour Hadi into exile. They are fighting to restore Hadi's internationally recognized government.

The Houthis, who say their revolution is against corruption, control Sanaa and most population centers. The strikes hit the al-Jeraf neighborhood in north Sanaa.

Houthi-run Masirah TV said a fire broke out in a plastics factory as a result of air strikes early on Wednesday.

The U.N. has said that a blast in Sanaa near two schools on Sunday killed 14 children and injured more.

"It was almost lunchtime and students were in class. The blast shattered the windows and unleashed a burst of shrapnel and broken glass into the classrooms," said Geert Cappelaere, UNICEF's Middle East head.

cnxps.cmd.push(function () { cnxps({ playerId: '36af7c51-0caf-4741-9824-2c941fc6c17b' }).render('4c4d856e0e6f4e3d808bbc1715e132f6'); });

It is unclear what caused the blast and U.N. Yemen aid coordinator Lise Grande called for efforts to pinpoint the circumstances "that led to this tragedy."

Yemen’s war has killed tens of thousands of people - some of them by coalition air strikes - and driven 10 million to the brink of famine. The country is also suffering its third major outbreak of cholera since the conflict began.

A peace process that began with a December agreement has stalled and, although a ceasefire largely holds in Hodeidah, Yemen's main port, violence continues elsewhere and has escalated in recent weeks.

The Saudi-led coalition carried out air strikes in Yemen against two Houthi targets in Sanaa, the capital, early on Wednesday, its spokesman said.The U.N. is trying to get the parties to pull troops out of Hodeidah and complete a prisoner exchange, two confidence- building measures which could pave the way for further talks.