In the fighting both sides used heavy weapons, security sources said.
After Zarb-i-Azb offensive in North Waziristan tribal region, the military has launched Khyber I operation in Khyber tribal region after reports about the presence of militants in farflung Tirah Valley.
Lashkar-i-Islam and other militant groups operating in the areas being targeted in the Khyber operation.
An insurgency of Taliban militants has been raging in Khyber tribal region, a Federally Administered Tribal Area of Pakistan. The region stretches from the Tirah valley down to Peshawar, the capital city of Khyber Pakhtunkhwa province.
Nangarhar province of Afghanistan located in the west of Khyber region.