The aftermath of an air strike in Dhamar, Yemen, Sept. 1, 2019. Photo: Reuters / Ahmed al-Ansi.

The United Nations envoy on Yemen called on Thursday 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 United Nations describes as the world’s biggest humanitarian crisis, with millions on the verge of famine.

The strikes 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 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 strikes 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 strikes.

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.

“For what sin is this child and a baby only days old bombed?” another employee, Ahmed al-Aawag, said.

The coalition, which receives weapons and intelligence from Western allies including the United States and Britain, was last month removed from a UN blacklist several years after it was first accused of killing and injuring children in Yemen.

The conflict has killed more than 100,000 people since the alliance intervened in Yemen in March 2015 shortly after the Houthis ousted the Saudi-backed government from power in Sanaa.

Griffiths has been holding virtual talks between the warring parties to agree a permanent ceasefire and confidence-building steps to restart peace negotiations last held in December 2018.

The conflict is largely seen regionally as a proxy war between Saudi and Iran. The Houthis say they are fighting a corrupt system.