Many Taliban and al-Qaeda members who fled to the region after US-led forces drove them out of Afghanistan in late 2001 have found support in the tribal areas.
"The army is fighting well-trained militants. There are linkages with Afghanistan. Many of them are getting money and weapons from across the border," Arshad said.
Peace deal scrapped
There has been a rise in fighting since July when tribal groups in the semi-autonomous region scrapped a peace deal with under which they would have taken greater responsibility for security in return for a withdrawal of Pakistani government forces.
|"There are linkages with Afghanistan. Many of |
them are getting money and weapons from across the border"
Major-General Waheed Arshad,
Pakistan military spokesman
Nearly 300 people have been killed in attacks, mostly suicide bombings, since army commandos stormed a mosque and religious school in Islamabad, Pakistan's capital, the same month.
In neighbouring South Waziristan, pro-Taliban fighters have been holding more than 200 Pakistani soldiers since capturing them in late August. They are demanding an end to all military operations in the tribal areas bordering Afghanistan.
Kamal Matinuddin, a retired lieutenant general in the Pakistan army, told Al Jazeera that fighters have been causing "a lot trouble for the army" in the region because of its lack of control over the area.
"There is almost a civil war-like situation in the tribal areas," he said. "It is very difficult for the army to move because their convoys are being ambushed, and so it is a very difficult operation the army has taken upon itself."
Pervez Musharraf, the president who is waiting for the supreme court to rule on the legality of his controversial re-election on Saturday, has said "terrorism" is one of the biggest challenges to the country.
But the conflict has reinforced opposition among many Pakistanis, mainly in the conservative northwest, to Musharraf over his support for the US's so-called "war on terror".