Yemeni security officials say a car bomb exploded behind a military hospital in the capital, Sanaa, causing dozens of casualties, among them civilians.

The officials, close to Yemen's Houthi rebels, said the blast on Monday targeted the homes of several Houthi leaders, but did not give further details on how many people were killed or wounded.

Houthi security forces cordoned off the area after the explosion and prevented anyone from entering.

In Shabwa province, tribal leaders and Houthi officials say gunmen attacked a motorcade carrying the Houthi provincial governor and a pro-Houthi military commander, wounding both of them.

The officials spoke on condition of anonymity because they weren't authorized to brief journalists.

The fighting in Yemen pits Shiite rebels known as Houthis against forces loyal to the exiled president.