Authorities in Bannu say the suicide bomber exploded a small truck full of explosives, destroying the police station and surrounding buildings.
District Police Officer Iqbal Marwat says nearby civilians were wounded, but most of the casualties were police officers.
He says the attacker tried to ram the vehicle through the main gate, but then detonated the bomb after police opened fire.
Local media are quoting a representative for the outlawed Tehrik-e-Taliban Pakistan as taking responsibility for the bombing.
This is the first time the alliance of more than a dozen militant groups with links to al-Qaida has claimed responsibility since its former leader Baitullah Mehsud was reportedly killed in a U.S. missile strike. Analysts had suggested the group was in disarray following Mehsud's death. Hours later in Peshawar, officials say an attacker in a parked car threw a grenade at a crowd of people outside the Askari Bank before exploding in the car.
No one has claimed responsibility for the attack. Senior police official Ghafoor Afridi tells VOA that the bomber bypassed multiple security checkpoints.
"There was checking all around. But somehow, it is not possible to check all vehicles, so they might have slipped a vehicle inside and exploded it," said Afridi. Saturday's attacks come as the Pakistani military works to expand its offensive against the Taliban from in around Swat valley to the north to south Waziristan also Thursday a suspected U.S. missile strike killed at least 12 people believe to be militants and the nearby north Waziristan tribal region, but newest considered a gateway to the Afghan border area which has a strong al-Qaida and Taliban presence.
Sean Maroney, VOA News, Islamabad
