Ten cops were martyred while six were injured in a late-night attack on the Chodwan police station in Dera Ismail Khan on Monday, police said.
The attack comes three days before the general elections are scheduled to take place on February 8 (Thursday).
Regional Police Officer (RPO) Nasir Mehmood confirmed the casualties to Dawn.com.
“More than 30 terrorists launched an attack from three directions. There was an exchange of fire for over two-and-a-half hours,” Khyber Pakhtunkhwa provincial police chief Akhtar Hayat Gandapur told AFP.
Gandapur told AFP the attackers briefly seized control of the police station during the assault in the early hours of Monday.
Malik Aneesul Hassan, the deputy superintendent of police in Draban, told Reuters that after entering the building, the militants “used hand grenades which caused more casualties to the police”.
Security concerns in Khyber Pakhtunkhwa and Balochistan have risen as both provinces have witnessed multiple attacks over the past few days.
The Election Commission of Pakistan (ECP) and the security apparatus had reviewed the law and order situation last week, stating that polls would be held at their scheduled time.
Caretaker KP Chief Minister Justice (rtd) Arshad Hussain Shah condemned the attack and expressed his grief over the loss of lives.
In a statement, he conveyed his condolences to the families of the martyrs and prayed for the speedy recovery of the injured.
CM Shah said KP police had rendered “eternal sacrifices” for peace in the province and that “such cowardly attacks would not demoralise them”.
He asserted that the government would help the bereaved in “every way possible”.
Additional input from AFP and Reuters
