Yemen's Defense Ministry says clashes in the south between al-Qaida and pro-government fighters have killed four.

A ministry statement on Friday says the fighting in the town of Jaar in Abyan province left two militants and two pro-government militiamen dead. Five were wounded and three al-Qaida members were captured.

The statement says the Popular Committees militiamen - who have sided with the army in the struggle against al-Qaida - attacked the militants on Thursday to avenge the killing of one of its members.

The U.S. considers Yemen's al-Qaida branch as the terror group's most dangerous offshoot. Washington has helped Yemeni troops with airpower and advisers during last year's offensive to drive the militants out of large areas they seized during the political turmoil related to Yemen's 2011 uprising.

Meanwhile, security officials said unknown gunmen fired shots Friday at the house of Transport Minister Waed Bathib in Aden and hurled a hand grenade before fleeing. The grenade exploded near the house's wall but caused material damage only. It was not clear who was behind the attack.

Bathib survived an assassination attempt in August when shots were fired at his car in Aden from another car. Nobody was arrested and that the identities of the attackers were unknown.

Bathib is a member of the Socialist Party that ruled former South Yemen before it was united with the north in 1990.

The security officials spoke on condition of anonymity in line with regulations.