Pakistani troops killed 15 militants in a clash early on Saturday in the Khyber tribal region near the Afghan border as part of a major anti-insurgent offensive, the military said.
It said a group of militants were spotted near a military post in Mastak Sub Sector in the Tirah valley.
"Troops on post valiantly engaged terrorists and surrounded them, intense gun battle took place.... 10 terrorists were killed, three soldiers were also injured in action," the military said in a statement.
Khyber is one of seven autonomous tribal districts along Pakistan's mountainous western border which became a hotbed of Islamist militants following the US-led invasion of neighbouring Afghanistan in 2001.
The military launched its latest offensive in Khyber in October 2014, four months after a similar operation began in North Waziristan district, triggered by a bloody Taliban attack on Karachi airport that sank faltering peace talks.
Air strikes, artillery, mortars and ground troops have all been used to take back territory. Both conflict zones are off-limits to journalists, making it difficult to verify the number and identity of those killed.