Pakistani army has launched another offensive against Taliban militants in North Waziristan, pounding their hide-outs in the mountainous region.
The officials say the area is the "latest Taliban stronghold" and an important smuggling route to Afghanistan.
Local media reported at least 17 militants killed after fighter jets bombarded the Shawal Valley and destroyed vehicles that belong to the militants.
The Pakistani Taliban controlled almost all of North Waziristan until Pakistani troops launched the operation Zarb-e-Azb there in June 2014. The latest offensive is part of this operation. The army says Taliban still controls some areas and new offensive aims to clear the Shawal Valley.
Residents told Reuters that hundreds of troops moving from the north and south to the valley as a curfew in place and phone lines are cut. They also said many people are preparing to go to safer places because of heavy fighting.
Meanwhile a gunman shot dead a senior Pakistani police officer in Karachi on Friday, police said, the third incident targeting senior officers in the city.
"The killing of three senior ranking officers in 15 days is quite unusual," a senior police officer told Reuters, adding militants are targeting more senior officials recently.
Friday's killing of Superintendent Ejaz Haider, a Shiite, is claimed by both Taliban and a breakaway group of Pakistani militants, but neither of them could be verified. The shooting follows Wednesday's attack on Shiite passengers in a bus that killed 45 people.