Members of an armed group attacked the security post near Mir Ali in the early hours of Saturday, the army's communication service (ISPR) said in a statement.

"The terrorists rammed an explosive-laden vehicle into the post, followed by multiple suicide bombing attacks, which led to (the) collapse of (a) portion of a building," the statement said, adding that five soldiers were killed.

Clashes followed, and during an exchange of fire a 39-year-old lieutenant colonel and a 23-year-old captain died, the ISPR added.

All six assailants died in the attack.

Pakistan was once plagued by near-daily bombings, prompting a major military clearance operation in the former tribal areas starting in 2014.

North Waziristan, where Saturday's attack took place, has historically been a hive of militancy and was the target of a long-running Pakistani military offensive and US drone strikes during the post-9/11 occupation of Afghanistan.

Analysts say militants in the former tribal areas have become emboldened since the Taliban's return to power in neighbouring Afghanistan in 2021.

Pakistan's home-grown Taliban group, Tehreek-e-Taliban Pakistan (TTP), has waged a growing campaign against security officials.

Islamabad has accused Kabul's Taliban government of harbouring TTP fighters, allowing them to strike on Pakistani soil with impunity. Kabul has consistently denied the allegations.