At least four soldiers have been killed in a suicide car bomb attack on the security forces' headquarters in Yemen's southern city of Aden.
Three officers were also wounded in the attack, which happened early on Tuesday morning in the Khormaksar district, a security source told the BBC.
The blast caused heavy damage to the compound, and blew out doors and shattered windows in nearby buildings.
Two "terrorist elements" were arrested and were being questioned, police said.
One report said they had attempted to ram an explosives-filled car through the security headquarters' gate shortly after the first bombing.
Witness Jazim al-Sulwi told the Associated Press that the after the explosion guards had started firing indiscriminately at people who ran out of nearby hotels and homes onto the street.
Analysts said the attack bore the hallmarks of al-Qaeda in the Arabian Peninsula, which earlier this month carried out a co-ordinated attack on the defence ministry complex in Sanaa, killing more than 50 people.