Gunmen have attacked the headquarters of Yemen's domestic intelligence agency in the city of Aden and freed several detainees. At least 10 security officers were killed.
Fighting between the gunman and security guards began at 7.40am local time (0440 GM) on Saturday and lasted more than an hour.
The attackers were wearing military uniforms and had rocket grenades and machine guns.
Ten men escaped from the same building in 2003. One was later convicted of involvement in the plot to blow up the USS Cole in the port of Aden in 2000.
The BBC reports the Yemen government is facing three different threats: from al-Qaeda, southern secessionists and a rebel movement in the north.
Earlier in the week, Al Qaeda's wing in Yemen threatened to respond to a government crackdown against it.
