The Pakistani army says it has destroyed a major al-Qaeda hideout in its biggest ever operation in the North Waziristan tribal region.
The army says the raid shows again that al-Qaeda is on the run
The military says it has arrested more than 20 suspected militants near the Afghan border and seized what it called a Chinese-made spy plane.
The army says the operation, involving helicopter gunships and thousands of troops, is still going on.
Some of the men arrested were described as "important figures".
Some were said to be foreigners, although no more information was given on who they were or where they had come from.
The commander in charge of the operation said sophisticated equipment had been seized, including a small, Chinese-made remote controlled drone, which he said had been used by the militants to spy on army movements and positions in the area.
The 'drone' on display - toys like this can be bought in shops and on the internet
The drone was shown to the media along with communications equipment which the army said had been used to give instructions to fighters in Afghanistan.
An officer from the Signal Corps said the drone, believed to be the first of its kind found in Pakistan, was equipped with a sophisticated, wide-angle camera.
However, it has emerged that the kind of plane on display is similar to model planes that can be freely brought on the open market.
The BBC's Jannat Jalil in Islamabad says the Pakistani army is heralding its operation as another sign it has al-Qaeda on the run.
The operation comes as President Pervez Musharraf, on a visit to the United States, says Pakistan is winning the war on terrorism.
He has been under pressure to show the army is also committed to rooting out Taleban fighters who might be using Pakistan as a base to launch attacks on Afghanistan.
The Afghan government has repeatedly accused Pakistan of not doing enough to stop the Taleban from carrying out cross-border raids.
Pakistan denies this and says it has boosted the tens of thousands of troops it already has on the border to stop militants disrupting Sunday's elections in Afghanistan.
It is thought al-Qaeda leader Osama Bin Laden might be in the tribal area but he has not been traced in three years of military operations by Pakistan.