The militants attacked the check posts in Shindara and Khazana Kandao in Orakzai Agency early this morning.
Pakistani troops repulsed the attack, killing 20 militants and injuring another 20.
At least four soldiers were also injured in the shootout. They have been brought to Peshawar for treatment.
The attack on the check posts came a day after, 23 militants were killed in airstrikes by Pakistani fighter jets in the restive North Waziristan tribal region.
More From This Section
Orakzai is one of Pakistan's seven semi-autonomous tribal regions in the northwest, where militants linked to Pakistani Taliban and al-Qaeda are believed to have their stronghold.
The region was a hideout of Tehreek-i-Taliban Pakistan (TTP) chief Hakimullah Mehsud before he was killed in a US drone strike in North Waziristan in 2013.
Pakistani army in June launched a military campaign against militants in the tribal regions of North Waziristan and Khyber and intensified the operation after the recent Taliban attack on an army-run school in Peshawar that killed 150 people, mostly children.
According to ISPR, the media wing of the army, it has killed over 1,200 militants since the start of operation Zerb-e-Azb in June against militants in North Waziristan.