Kabul, Afghanistan (CNN) -- Taliban suicide bombers attacked Afghanistan's regional spy headquarters in Ghazni city early Thursday, leaving 21 people dead and more than 150 civilians wounded, a government official said.
Nineteen of the dead were the suicide attackers. The remaining two were members of the National Directorate of Security personnel.
The NDS is the nation's spy agency.
A Taliban spokesman claimed responsibility for the attack.
The assault began when one of the suicide attackers detonated an explosives-filled truck at the front gate of the spy agency, said Shafiq Nang, a spokesman for the governor of Ghazni province. Twelve of them stormed the NDS. Six others hit the Rapid Reaction Police headquarters in the city.
For the next hour, Afghan security forces battled the Taliban attackers until all of them were killed, he said. Most of the injuries were the result of broken glass and collapsed roofs from the explosion.