Pakistan's military said Tuesday it had killed 15 militants in air strikes along its restive border with Afghanistan on Tuesday as part of a major offensive to clear Taliban and Al-Qaeda strongholds.

The strikes were carried out in the Alwara, Khar Tangi and Maizer areas of North Waziristan's tribal region, the bastion of Islamist insurgents who rose up against the state in 2004.

Pakistan began its operation in June 2014, after a bloody Taliban attack on Karachi airport finally sank faltering peace talks earlier that year.

"Fifteen terrorists were killed and eight of their hideouts destroyed in the aerial strikes today," the military said in a brief statement.

The conflict zone is remote and off-limits to journalists, making it difficult to verify the army's claims, including the number and identity of those killed.

The bombings came a day after a US drone strike, which was targeting three compounds belonging to fighters from the Haqqani network in the Kurram tribal district, injured one militant, according to Pakistani security officials.

Pakistan officially denounces such strikes as a violation of its sovereignty, though analysts believe the two countries coordinate at least some of the attacks.

The Haqqani network targets Afghan, US forces and Indian interests in Afghanistan and some analysts believe it is linked to Pakistan's shadowy security establishment.

Pakistan's Islamist insurgency began after the US-led invasion of neighbouring Afghanistan in 2001 which led to a spillover of militants across the border and a surge in recruitment for Pakistani militant groups.

Pakistan's relative success in fighting militancy stands in marked contrast to Afghanistan, which is facing record numbers of civilian casualties following the withdrawal of NATO combat troops at the end of 2014.