Pakistan's military Thursday claimed to have killed at least 47 Taliban fighters in two days of airstrikes in the restive northwest as part of anti-insurgent offensives that began last year.

The latest strikes hit the Datta Khel area of North Waziristan tribal district, close to the Afghan border, considered a stronghold of Taliban insurgents. The area has been repeatedly targeted by US drones in the past.

"Twenty-two terrorists were killed in precise aerial strikes late last night in (an) area (close to) Datta Khel in North Waziristan Agency," the military said in a statement Thursday.

The military has been stepping up its response Pakistan's Islamist insurgency, which has claimed the lives of tens of thousands of civilians since 2004 when Al-Qaeda and Taliban militants fled from Afghanistan to its tribal areas.

Thursday's attacks come the day after 20 militants were killed in the Tirah valley of Khyber tribal district, where the Pakistani Taliban and Lashkar-e-Islam groups have strongholds.

"In precise aerial strikes in Tirah, Khyber, today, 20 terrorists -- including three suicide bombers -- were killed. Destroyed hideouts of terrorists include their ammo and ration dumps," the military said in a statement late Wednesday.

In another incident late Wednesday, the military said it had killed five insurgents in a search operation in Shakto area of South Waziristan tribal district.

Khyber is one of seven autonomous tribal districts along Pakistan's mountainous western border, which became a hotbed of Islamist militants following the US-led invasion of neighbouring Afghanistan in 2001.

The military began its latest offensive in Khyber in October 2014, four months after by a bloody Taliban attack on Karachi airport ended peace talks and triggered a similar operation began in North Waziristan district.

Airstrikes, artillery, mortars and ground troops have all been used to take back territory.

Both conflict zones are off-limits to journalists, making it difficult to verify the number and identity of those killed.