Sanaa: Dozens of people, many of them civilians, were killed in air strikes by a Saudi-led coalition on the southwestern Yemeni city of Taiz, an aid organisation and Houthi media said on Friday.
Houses were reduced to rubble and many victims were unable to reach hospitals, Medicins Sans Frontieres said.
Saba news agency, which is run by the Houthi movement, said the air raids late on Thursday targeted Taiz`s palace and the Sala neighbourhood, which has a dense Houhti population.
Taiz has become the latest focus of fighting for supporters of President Abd-Rabbu Mansour Hadi, who was driven into exile in Saudi Arabia by Houthi fighters in March. Yemen`s third-largest city, it is considered its cultural capital.
The Saudi-led Gulf Arab coalition intervened on the side of Hadi loyalists in March. They have pushed back Houthi forces who had taken control of most of the country but the civilian death toll has drawn growing criticism from international aid and rights groups.
Medicins Sans Frontieres put the toll from Thursday`s raids at as a high as 65, including at least 17 children and 20 women.
"The deaths occurred when the strikes hit civilian and homes in the area," Salah Dongu`du, Medicins Sans Frontieres project coordinator in Taiz, said in a statement.
"Those who survived the bombings are searching through the rubble with their bare hands in the hope of finding survivors, as well as the bodies of victims of the attack," Dongu`du said.
Saba news agency had earlier put the death toll at 43, with 50 wounded. Medical sources said Houthi attacks in the city killed 13 people, including seven children.
There was no immediate comment from officials from the Saudi-led coalition.
Dongu`du said patients and Medicins Sans Frontier staff were unable to reach hospitals due to the heavy fighting and airstrikes.
"MSF is trying to provide first aid kits to nurses and doctors so they can treat injured people who are not able to reach the hospital, but we know it is not enough," he said.
Local officials told Reuters that Houthi fighters fired mortars at Taiz`s Asifrah neighbourhood and al-Masbah, east of the city, in a bid to drive out Hadi supporters. The barrages destroyed a power plant in the city.
Gains by the pro-Hadi forces have put them in control of parts of the city.
The southern port city of Aden was retaken from the Houthis last month with the help of coalition air strikes and weapons deliveries. The Houthis, a Shi`ite Muslim sect traditionally based in Yemen`s north, still hold the capital Sanaa, which they seized last September.
The civil war has killed more than 4,300 people and caused a humanitarian crisis. Diplomats and air groups have appealed for a ceasefire.
Saudi Arabia sees the Houthis as proxies for Iran, its rival for regional leadership. The Houthi movement says it is trying to root out corruption and defeat Islamist militants linked to al Qaeda.
