Pakistan said Tuesday it has killed 21 militants in air strikes and ground operations that began overnight in a northwest border region where it is carrying out an offensive to clear Taliban strongholds.

Pakistan said Tuesday it has killed 21 militants in air strikes and ground operations that began overnight in a northwest border region where it is carrying out an offensive to clear Taliban strongholds.

Military spokesman Asim Bajwa said the strikes, which took place in the Shawal Valley of North Waziristan tribal district, began Monday night and continued into Tuesday.

"Ops continue. Imp heights & passes along Pak-Afgn Bdr secured. Valley's sanitization in progress," he said on Twitter.

It was not possible to confirm how many people were killed in the offensive, nor whether they were indeed combatants, as journalists are denied access to the conflict zone.

Pakistan began its operation to clear Taliban and Al-Qaeda strongholds in North Waziristan in 2014, and claims to have killed more than 3,750 militants since then with no civilian casualties.

In late February the army said it was entering the final phase of the operation, but offered no further details.

Meanwhile, the toll from a deadly Taliban suicide bombing on a court complex in northwest Pakistan rose Tuesday after a victim died overnight, officials said.