"15 terrorists were killed in ground action by security forces early morning today," army said in a statement.
The offensive was part of Khyber Two operation which has been going on in the Khyber district.
A group of about 30-35 terrorists was observed near a post in Mastak Sub Sector in Tirrah.
"Troops on post valiantly engaged terrorists and surrounded them. Intense gun battle took place. Three soldiers were also injured in action," it said.
Pakistan forces are involved in intensive fight with militants in the Tirah Valley of Khyber.
So far, more than 100 militants have been killed in over two weeks of fighting.