Iranian-allied fighters controlling much of Yemen said on Friday airstrikes led by Saudi Arabia killed 43 people in the central city of Taiz.
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 the Houthi fighters. Medical sources said Houthi attacks on the city killed 13 people, including seven children.
Reuters was not immediately able to independently verify the information on either side. There was no immediate comment from officials from the Saudi-led coalition.
The Saba news agency run by the Houthis said the Saudi-led air raids late on Thursday targeted Taiz's republican palace and the city's Sala neighborhood, which has a dense population of the Houthi group that dominates northern Yemen.
It said 50 people had been injured and some of the 43 killed were found dead in the ruins of buildings destroyed by the bombing in Sala.
Meanwhile, local officials told Reuters that Houthi fighters fired mortars at Taiz's Asifrah neighborhood and al-Masbah, east of the city, in a bid to drive out Hadi's supporters. They said the shelling destroyed a main power plant in the city.
Houthi militants gather on the rubble of the offices of the education ministry's workers union, destroyed by Saudi-led airstrikes, in Yemen's northwestern city of Amran, August 19, 2015.
Gains by the pro-Hadi forces have put them in control of parts of the city, located between the Houthi dominated north and the south, where Hadi supporters have been cheered by several strategic gains in the past month.
The southern port city of Aden was retaken from the Houthis last month with the help of heavy Arab airstrikes and weapons deliveries. The Houthis, however, still hold the capital Sanaa.
The Saudi-led alliance began its airstrikes in late March when the Shi'ite Houthis entered Aden.
The civil war has killed more than 4,300 people and left diplomats and other groups appealing for a ceasefire to spare civilians and alleviate a mounting humanitarian disaster.
Saudi Arabia sees the Houthis as proxies for Iran, while the group, which hails from the Zaydi branch of Shi'ite Islam, says it was trying to root out corruption and defeat Islamist militants linked to al-Qaida.