A car bomb targeting a military facility killed seven people and wounded 18 others on Sunday in Aden, the main city in southern Yemen, medics and soldiers said.
Medics gave the toll, while soldiers told AFP the blast went off as troops prepared to leave the facility for Abyan province, where security forces are engaged in fierce fighting with militants suspected of ties to al-Qaeda.
"We were preparing to leave for Abyan when a car came in front of the gate of the camp, and then there was a huge explosion," said one soldier who survived the attack.
Among those killed was a lieutenant colonel, according to one medical official.
Militants belonging to a group called the "Partisans of Sharia (Islamic law), which has been linked to al-Qaeda, took over much of Zinjibar, the capital of Abyan province, in May.
Thousands of people have been displaced by fighting in Zinjibar between security forces and the militants.
Ayad al-Shabwani, a leader of the Yemen-based al-Qaeda in the Arabian Peninsula, or AQAP, was killed during fighting near Zinjibar on Tuesday, a military official said.
At least 12 soldiers have been killed and dozens wounded since in battles around the same area, according to officials.