Pakistan's military says it has it killed 23 fighters in aerial strikes across North Waziristan tribal district in the northwest region near the Afghan border.

In a statement issued to the media on Friday, the military said: "Today in precise aerial strikes carried out on terrorists hideouts in Zerom, Ismail Khel, and Datta Khel in North Waziristan, 23 terrorists were killed."

In June, the army began major offensives in North Waziristan aimed at clearing the area of armed groups, including the Taliban, after a raid on Karachi airport ended faltering peace talks.

Residents have said many civilians have died in air strikes, but as the conflict zone is off-limits to journalists, there is no way to independently verify the number and identity of those killed.

North Waziristan has become a major base for the Tehreek-e-Taliban Pakistan (Pakistani Taliban), which rose up against the state in 2007.

The US has long called for action in the area because the armed groups have targeted NATO forces in neighbouring Afghanistan.

Pakistan's army says it has killed more than a thousand fighters and has lost 86 soldiers since the start of the operation.