At least six people were killed in the southern Yemeni city of Lawdar on Friday in clashes between government forces and al-Qaeda linked militants, a local official and tribal sources said.

Yemen's military launched an offensive five days ago against Islamic insurgents who had attacked a military camp outside Lawdar.

The sources said the dead were three Islamist militants and three tribesmen fighting alongside government forces.

A local official said the Yemeni air force bombed two sites held by Ansar al-Sharia (Partisans of Islamic Law), a group affiliated with al Qaeda, but no casualties were reported.

The group seized control of a significant amount of territory in Abyan during the turmoil that led to the replacement of President Ali Abdullah Saleh by his deputy. Saudi Arabia and the United States hope the political deal will prevent al Qaeda from getting a foothold near oil shipping routes.

The conflict with Islamists in the south is only one of several challenges facing the new president, Abd-Rabbu Mansour Hadi, who took office vowing to fight al Qaeda.

At least 150 people have been killed in fighting and air strikes in the Lawdar area since Monday when Ansar al-Sharia attacked a military camp there, according to officials.

(Reporting by Mohammed Mukhashaf; Writing by Mahmoud Habboush; Editing by Janet Lawrence)