According to district police officer Khan Khel, the incident took place in the Dazha Ghundai area on the outskirts of Wana, where sub-inspector Mehmood Khan Wazir was gunned down in front of his residence, reported Dawn News.
The gunmen, who were riding a motorcycle, gunned down the policeman on the spot.
Police officials told the newspaper that the officer was on leave and had returned home from the Wana police lines just days earlier.
The gunmen escaped from the spot after the attack.
The entire area was cordoned off after the attack.
A search operation has been launched to probe the incident.