Yemeni security officials say at least 10 fighters from a pro-government militia have been killed when suspected al-Qaeda militants targeted their convoy with two car bombs.
The officials say the attack took place late Sunday in the Yafea area in Lahj province, where Yemen's al-Qaeda branch controls several areas, including a large base in which it has stockpiled heavy weapons looted from army depots elsewhere.
The officials spoke on condition of anonymity because they were not authorised to talk to the media.
Al-Qaeda has taken advantage of Yemen's civil war to gain a foothold in several southern Yemeni areas.
The war pits troops and militiamen loyal to the internationally recognised government, backed by a Saudi-led coalition, against Shiite Houthi rebels and a former president's loyalists.