SANAA - The United Nations envoy for Yemen has called for a transparent investigation into air strikes that killed at least 11 civilians in al-Jawf province, saying resurgent violence is complicating UN-led efforts to end the five-year war.

Security is deteriorating anew as Yemen faces the coronavirus pandemic and what the UN describes as the world's biggest humanitarian crisis, with millions on the verge of famine.

The raids were the third such incident since June. The Saudi-led coalition battling Yemen's Iran-aligned Houthi group has said it is investigating reports of civilian deaths in Wednesday's attack and in the Hajjah region earlier this week.

"We deplore yesterday's air strikes in #AlJawf ... A thorough & transparent investigation is required," envoy Martin Griffiths tweeted, describing attacks on civilians as reprehensible.

The UN humanitarian coordination office in Yemen said at least 11 civilians were killed. The Houthi health ministry raised the death toll to 24 after initially saying nine people, including two children, were killed when coalition air raids hit homes.

The Houthis have recently stepped up cross-border missile and drone attacks on Saudi cities as well as military operations on the ground. The coalition has retaliated with air raids.

At al-Thawra hospital in the Houthi-held capital Sanaa, where some of the injured were taken, a child writhed in bed with a chest drain and bandaged shoulder and legs.

A 15-day-old baby died from his wounds, hospital employee Ahmed Sanad, told Reuters news agency.

"For what sin is this child and a baby only days old bombed?" another employee, Ahmed al-Aawag, said.(FA)