The Saudi-led coalition fighting in Yemen carried out air strikes against two Houthi targets in the capital Sanaa early on Wednesday, its spokesman said.
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.
Houthi-run Masirah TV said a fire broke out in a plastics factory as a result of air strikes early on Wednesday.
Saudi Arabia leads a Western-backed alliance of Yemeni and Arab forces that has been fighting the Iran-aligned Houthi movement in neighbouring Yemen since March 2015, after Houthi forces drove Yemeni President Abd-Rabbu Mansour Hadi into exile.
They are fighting to restore Hadi's internationally recognised 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.
The roof was blasted off a large industrial building and machinery was damaged, Reuters footage showed. Bystanders pointed to powder they say would have been turned into plastic in the factory.
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 as the United Nations tries to get the parties to pull troops out of Hodeidah, Yemen's main port, and complete a prisoner exchange.
These confidence-building measures could pave the way for further talks.
Although a ceasefire agreed in December for Hodeidah largely holds, violence continues elsewhere and has escalated in recent weeks.
A blast hit Sanaa near two schools on Sunday, the United Nations and Houthi-run media has said.
"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.
Funerals for 12 of the killed pupils, all girls, were held on Wednesday, their coffins carried by a crowd through the streets of Sanaa.
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".
As well as deaths from conflict, Yemen's war has pushed more than 2 million people from their homes - exacerbating disease, poverty and hunger.
Aid group Medecins Sans Frontiers (MSF) said a flare up in fighting in the Abs region in recent days has forced 18,000 from their homes, adding to the tens of thousands already displaced in that area.
"MSF calls on all warring parties to ensure the protection of civilians," it said in a statement.
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