ADEN/SANAA (Reuters) - Saudi-led forces launched overnight air strikes on Yemen’s capital, described by one resident on Sunday as the worst in a year, as the United Nations struggles to implement a peace deal.

A spokesman for the Saudi-led coalition said its warplanes attacked seven military facilities used for drone operations in Sanaa, which is held by rival Houthi forces.

Yemen’s nearly four-year-old civil war, which pits the Iran-aligned Houthi movement against the Saudi-backed government of Abd-Rabu Mansour Hadi, has killed tens of thousands and left millions on the brink of starvation.

Saudi-owned Al Arabiya television said the overnight targets included al-Dulaimi Air Base, a drone storage site, and military training sites.

Medical workers and residents told Reuters at least two civilians were killed, and others injured, and that the raids also damaged homes.

Houthi-run al-Masirah TV said on Sunday that the coalition had conducted 24 air strikes on Sanaa since Saturday evening, including four on the air base. It said a plastics factory was also hit, causing a large fire.

Reuters footage showed a large crater next to the factory, and damaged homes nearby.

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“The raids were very violent, the likes of which we have not seen for a year,” Sanaa resident Arwa Abdul Karim told Reuters. “The house shook so much we thought it would fall on our heads.”

FRAGILE TRUCE HOLDS IN HODEIDAH

The escalation in fighting, which follows a deadly Houthi drone attack last week on a Yemeni government military parade, augurs badly for a second round of U.N.-sponsored talks this month aimed at ending the war.

Hadi was ousted from power in 2014, and the Sunni Muslim coalition led by Saudi Arabia and the United Arab Emirates intervened in 2015 to try to reinstate him.

The United Nations is trying to implement a ceasefire and troop withdrawal agreement in the port city of Hodeidah, the main entry point for most of Yemen’s imports and aid.

In the first significant breakthrough in peace efforts, a deal was reached in talks in Sweden last month to avert a full-scale assault on the port.

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The truce has largely held in Hodeidah, which is controlled by the Houthis with thousands of coalition-backed forces massed on the outskirts. But the withdrawal of forces by both sides has stalled over disagreements over who would control the Red Sea city.

Rights groups have criticized the coalition for air strikes that have killed thousands of civilians at hospitals, schools and markets since 2015. They also criticize the Houthis for missile attacks on Saudi cities, including the capital Riyadh.

Western nations, including some which supply the coalition with arms and intelligence, have pressed Riyadh and Abu Dhabi to end the conflict that has pushed Yemen to the brink of famine.

The conflict is largely seen in the region as a proxy war between Saudi Arabia and Shi’ite Muslim Iran. The Houthis deny receiving any help from Iran and say their revolution is against corruption.