The Pakistani military say the air force has pounded militant hideouts in a tribal region along the Afghan border, killing 20 suspected militants.

It says three of the suspects were training future suicide bombers in the Tirah Valley of Khyber region.

Thursday's strikes came a day after warplanes killed 22 militants in North Waziristan, where the military last week claimed to have routed insurgents in a major offensive launched last year.

The local and al-Qaida-linked foreign militants have long used the mountainous border region as a safe haven to launch attacks in Afghanistan and Pakistan.

Since the operation started, Pakistan's military says more than 1,200 militants have been killed.

The militants want to topple the government to replace it with one governed by their own harsh brand of Islamic law.