The two car bomb attack targeted police training centre attached to the headquarters in Gardez, the provincial capital at around 09:30 am.
21 security force members and 20 civilians lost their lives in the attack, the Deputy Interior Minister, Murad Ali Murad told reporters at a news conference.
According to Murad, the injured people included 48 soldiers and 110 civilians.
The Acting Spokesman of the Interior Ministry in a Facebook page confirmed the death of Toryalai Abdeyani, the Provincial Police Chief in the incident.
At least four attackers were also killed, local security sources told Ariana News.
The Taliban claimed responsibility for the attack.