Local officials said the incident took place late Thursday night in Chamtal and Chahar Bolak districts.
Provincial police chief, Gen. Abdul Razaq Qaderi said a number of militants carried out attacks on police check posts late Thursday night.
Gen. Qaderi further added that four policemen were martyred and another policeman was injured following the clashes which continued for almost four hours.
He said over militants including their commanders were also killed during the clashes.
In the meantime, Taliban group spokesman, Zabiullah Mujahid claimed that seven Afghan forces were killed and three check posts were take by Taliban fighters.