Yemeni officials say the country's Shiite rebels have retaken ground from forces loyal to the internationally recognized government in two central provinces, with at least 85 fighters killed on both sides over the past three days.

The officials said Thursday the fighting has been taking place in Marib and Shabwa provinces. They say that in Shabwa's region of Bihan, along with the 85 killed, about 100 fighters have been wounded on both sides.

Security officials loyal to President Abed Rabbo Mansour Hadi say pro-government forces retreated due to lack of air support from the Saudi-led coalition.

All officials spoke on condition of anonymity because they were not authorized to talk to reporters.

Yemen's war pits rebels known as Houthis and their allies against Hadi's forces, backed by the Saudi-led coalition.