Pakistani authorities say they suspect suicide bombers were responsible for separate blasts that killed at least 15 people near a police training facility in the northwest town of Bannu.
Officials in Bannu say 20 other people were wounded in Thursday's attack, including the town's chief of police.
The attack was the second in as many days targeting local police in Pakistan's northwest
On Wednesday, a suicide bomber hit a tribal police patrol near the Khyber pass, killing at least 18 people, including 11 officers.
No group has claimed responsibility for the attacks, but Pakistani militants have been targeting local security forces and government institutions.
Officials say many of the attacks are retaliation for Pakistani military offensives as well as U.S. drone strikes against militants in areas bordering Afghanistan.
U.S. and Pakistani officials say they increasingly suspect a U.S. drone strike in the region last month killed the leader of the Pakistani Taliban, Hakimullah Mehsud.
Although Taliban spokesmen have denied the claim, they have not provided convincing evidence that Mehsud is still alive. U.S. and Pakistani officials have suggested the militants may be determining who will succeed Mehsud as leader before announcing his death.
Some information for this report was provided by AP, AFP.
