Pakistani troops overran two militant hideouts and killed 16 insurgents after heavy overnight fighting at a flashpoint near the Afghan border in which two soldiers also died, the military said on Sunday.
The fighting took place in the wake of a fresh military push in the Tirah valley in the tribal Khyber district, where the military has been targeting Taliban and Lashkar-e-Islam militia who threaten the nearby northwestern city of Peshawar.
Khyber straddles the NATO supply line into Afghanistan, used by US-led troops to evacuate military equipment ahead of their 2014 withdrawal, and officials say it is key to protecting security in Peshawar for historic elections next week.
"In a successful operation security forces last night captured Kismat Sur and Sanghar, two strong hideouts of militants in Tirah Valley," the military said in a statement.
"Sixteen militants were killed in the operation. Two security personnel embraced martyrdom and three were wounded," it said.
Independent verification of the death toll was not possible as the area is cut off to journalists and aid workers.
"Militants were seen fleeing from the area, leaving behind a huge cache of arms and ammunition," the statement added.
Pakistan will elect its new government for the next five years in polls on May 11.
The election of the national and four provincial assemblies will mark the first time a civilian government has completed a full term and handed over to another, in a country that has been ruled by the military for half its existence.
Campaigning has been marred by Taliban threats and attacks, which have killed 66 people since April 11, according to an AFP tally.
Pakistani troops have been fighting for years against homegrown insurgents in the area, which Washington considers the main hub of Taliban and al Qaeda militants plotting attacks on the West and in Afghanistan.