(CNN) Four assailants wearing police uniforms -- including two suicide bombers -- attacked a police headquarters in eastern Afghanistan's Logar province, killing 20 police officers and injuring eight others, a government spokesman said Tuesday.

The Taliban claimed responsibility for the attack in Pole Alam, the provincial capital, group spokesman Zabiullah Mujahid said in an email.

One suicide bomber detonated his explosives at the entrance to the headquarters, allowing three attackers to enter the complex, said Din Mohammad Darwish, a spokesman for the governor.

A second suicide bomber detonated in a canteen where police personnel were having lunch, and the other two attackers were killed in a gun battle with security forces, Darwish said.