Police in northwestern Pakistan say a suicide car bomber has killed four police officers and wounded at least eight other people.
Local authorities say the attacker blew up his explosives-laden car early Wednesday on the outskirts of Peshawar, the capital of Khyber Pakhtoonkhaw province.
The blast came a day after Pakistani security forces killed 11 militants in clashes in nearby Orakzai tribal region.
Pakistan's military launched an anti-Taliban offensive in Orakzai in March to target militants who are believed to have fled an earlier offensive in South Waziristan.
In other violence, gunmen killed a university professor in a drive-by shooting in Quetta, the capital of southwestern Baluchistan province.
