A suicide bomber blew up his vehicle at the entrance to the headquarters in Gardez city on Sunday and then a number of attackers stormed the compound, Abdullah Hasrat, a spokesman for the provincial governor of Paktia, told DPA.
Two assailants were killed immediately, according to Najib Danish, a spokesman for the Afghan Interior Ministry, while the third was still fighting.
Taliban spokesman Zabihullah Mujahid said the group took responsibility for the attack, claiming they had killed and injured tens of police officers.
The attack comes after an earlier Taliban attack that killed at least one Afghan and wounded seven US soldiers in an "insider attack" at a base in northern Afghanistan.
A US military official said seven American soldiers had been evacuated after being wounded in the incident at Camp Shaheen, the headquarters of the Afghan army's 209th Corps in the northern city of Mazar-i-Sharif.
A week ago three US soldiers were killed and a fourth wounded when an Afghan soldier opened fire on them at a base in eastern Afghanistan's Nangarhar province.