- The Taliban claim responsibility for the hours-long attack
- Both officers and civilians are among those killed and injured
Another 158 people were injured, said Murad Ali Murad, the country's deputy interior minister for security.
Two car bombs exploded at the gate of the police headquarters in the Paktia provincial capital of Gardez, Afghan Interior Ministry spokesman Najib Danish said.
Afterward, five attackers entered the building, leading to a five-hour gunbattle between them and police.
The Patkia provincial police chief was killed in the gunbattle, Danish said. The five attackers who entered the building were also killed.
The Taliban claimed responsibility for the attack, according to a statement from the group's spokesman, Zabiullah Mojahid.
Those killed included 21 police officers and 20 civilians, Murad said. At least 110 civilians and 48 police officers were injured.