Three security personnel were injured in the clash.
Twenty-three militants were killed in a prolonged exchange of fire with security forces in North Waziristan agency late on Wednesday.
According to military officials, terrorists tried to ambush a convoy of security forces which was returning from Khajori post.
The convoy had gone there to rescue injured soldiers attacked by a suicide bomber on Wednesday when they were offering prayers in a mosque at the post.
Security forces responded by encircling the terrorists and inflicted heavy casualties on them, the sources said. The exchange of fire continued for some time which resulted in the killing of 23 militants.
Three security forces personnel were also injured in the incident. The checkpost is located in Mirali tehsil of North Waziristan.
Suicide bomb attack
On Wednesday, a suicide bomb attack at the military checkpost killed five soldiers and injured over 30, according to news reports.
Dawn reported that a Tehreek-e-Taliban Pakistan (TTP) spokesperson claimed it was responsible for the suicide attack and that it was carried out to avenge the killing of former TTP leader Hakimullah Mehsud who died in a U.S. drone strike in November.