A military official says that armed tribesmen in Yemen have killed eight Shiite Houthi rebels.

He says the attack happened on a road north of Yemen's capital, Sanaa, and that the tribesmen fled the scene.

The Houthis, widely suspected of being linked to Iran, captured Sanaa last month and have since advanced on provinces to the west and south of the city.

Troops suspected to be loyal to ousted President Ali Abdullah Saleh opened fire on pro-secession protestors in the southern city of Aden, killing one person and injuring four, another military official said. The sit-in by thousands began two weeks ago in one of Aden's squares.

The two officials spoke on condition of anonymity because they were not authorized to speak to the media.