At least 17 people were reported killed and several others seriously injured in an explosion at a police station in Swat, in Pakistan's Khyber Pakhtunkhwa province.
The explosion occurred on the evening of Sunday, August 2.
Security forces believe the blast was a suicide attack and said they suspected that others may have assisted the attacker.
A Swat police officer said police stopped a man for a search as he entered the station, after which he detonated explosives worn on his body.
Search operations and an investigation were under way.
Prime Minister Shehbaz Sharif issued a statement expressing grief over the attack.
Pakistan has blamed Afghanistan's Taliban authorities for a worsening security situation in border areas and alleged support for militants; the Taliban have denied the allegation.