Two people were killed and 18 others including six women were injured when a suicide car bomber was rammed into the security headquarter in Sayon city in Hadhramout province early on Friday, a security source said.
The official says investigators are still trying to determine who was behind the attack.
The blast caused damage in some buildings in the area and a power outage, the source said.
The sources said this military site was exposed to an attack by voice bomb three months ago. No body claimed its responsibility for the attack