At least 11 fighters allied to the Southern Transitional Council in Yemen were killed on Friday in a car bombing in Abyan province.
The blast hit a military barracks in Wadi Omran, a local official told Yemeni news outlet South24. Soldiers were injured in the attack.
A STC official told The National the attack was probably carried out by Al Qaeda in the Arabian Peninsula, a group largely based in Abyan, a southern province on the Gulf of Aden. These attacks "can happen on occasions", the official said, without confirming the death toll.
Two STC members were killed in March in a bombing attack in Wadi Omran. Five fighters aligned with the group were killed in August last year, in an attack blamed on Aqap.
The STC has accused Aqap of co-operating with the Iran-backed Houthi rebels, which have taken control of large parts of northern Yemen.
Al Qaeda's branch in the country was formed in 2009 with the aim of becoming the ruling "Islamic regime". It engaged in direct attacks against other groups and had between 2,000 and 3,000 members, research by the Armed Conflict Location and Event Data Project found.
"Today, Aqap’s operational presence is stronger in Abyan and Shabwa governorates," the project said. "The group is also active in Hadramawt, Marib and Al Bayda governorates, with reported sleeper cells in Al Mahra, Aden and Lahej."