ISLAMABAD (AFP) - Pakistan's military said on Sunday it had launched a "comprehensive operation" to eliminate Taleban and Al-Qaeda militants in a restive tribal region bordering Afghanistan, a week after a brazen insurgent attack on the Karachi airport.

"On the directions of the government, Armed forces of Pakistan have launched a comprehensive operation against foreign and local terrorists who are hiding in sanctuaries in North Waziristan," a military statement said.

A military official in the main North Waziristan town of Miranshah told AFP that the coordinated operation - involving airforce, artillery, tanks and ground troops - has already started. "The operation has been named Zarb-e-Azb," the military statement said.

The announcement followed air strikes in the region earlier on Sunday that killed at least 80 insurgents, including Taleban members linked to the all-night siege on Karachi Airport.

Local security officials put the death toll far higher, saying that about 150 militants died in the air strikes, which primarily targeted Uzbek fighters in a remote area of tribal North Waziristan.

However, military officials stopped short of confirming this figure on the record saying the details of strikes were still pouring in.

After the announcement of the full-scale operation in the North Waziristan area, the security official on ground said that thousands of troops have been moved for action.

"Thousands of troops will participate in this action. You can roughly say 25,000 to 30,000 troops will be involved in the operation," the official said on the condition of anonymity because he is not allowed to speak to the media.

An operation on the area has been a long-standing demand of Pakistan's Western allies including the United States because of the presence of Al-Qaeda affiliated Haqqani network there.

But the authorities had held back from a final push - possibly fearing the blowback in Pakistan's major cities such as Karachi.