The military believes a "high-value" target is hunkered down in the besieged area in South Waziristan, but says it's uncertain if it is Osama bin Laden's Egyptian deputy, Ayman al-Zawahri, or another terrorist.
The Pakistani army says it will continue the assault until all the militants have surrendered or been killed, but if the battle drags on much longer and more civilians are harmed the government risks a backlash in the volatile tribal areas, reports CBS News Correspondent Tom Fenton.
In neighboring Afghanistan, aviation minister Mirwais Sadiq was assassinated Sunday in the western city of Herat. No suspects have been reported.
The American ambassador to Afghanistan said on Sunday that senior Taliban leaders still plot attacks on Afghan and U.S. targets from safe havens in Pakistan.
"We know several key Taliban figures are there and there is some sense that some of the remaining al Qaeda leaders are in the border area on the other side," Zalmay Khalilzad told The Associated Press.
"It doesn't serve Pakistan's interest for them to operate in Pakistan and to come across and attack Afghanistan or the coalition forces here," warned Khalilzad.
Pakistani troops faced no resistance on the sixth day of their siege along the Afghan border, involving 5,000-6,000 Pakistani forces.
The tribal peace council is to travel to the region Monday morning under the protection of a white flag, said Brig. Mahmood Shah, chief of security for the area. Fighting would stop while the council was negotiating, though Shah refused to call it a cease-fire.
The council will be carrying a list of three government demands: that the elders free 12 soldiers and two government officials taken captive earlier this week; that they hand over tribesmen involved in the fighting; and that they kick out any foreigners or show the military where to track them down.
"These tribesmen must hand over all the wanted people, or the operation will proceed," Shah told journalists in Peshawar, the provincial capital.
The operation that began Tuesday is the largest by Pakistan in its lawless tribal regions bordering Afghanistan since it threw its support behind the U.S.-led war on terrorism after the Sept. 11 attacks on America.
Fighting between Pakistani forces and 400-500 foreign militants and local Yargul Khel tribesmen abated Sunday, and Shah speculated that the militants were conserving ammunition.
"They may be facing a shortage of ammunition. Heavy firing has almost entirely stopped and they are only using light weapons," he said.
Shah said two Chechens were killed Sunday trying to break through a tight military cordon.
Pakistani forces took advantage of the lull to search homes.
The military has arrested more than 100 suspects so far, sending some of them to Peshawar, for interrogation. It displayed about 40 of them at a military base in Wana on Saturday, but did not identify them.
Shah on Sunday reiterated a pledge not to turn any captured locals over to a foreign country, presumably the United States. That pledge did not apply to the foreign militants.
Security officials said prisoners included Pakistanis, Arabs, Chechens, Uzbeks and ethnic Uighurs from China's predominantly Muslim Xinjiang province, but say it is difficult to distinguish the foreigners from locals, as they have often lived in the region for a long time and speak the local Pashto language.
Thousands of tribespeople have fled their homes, and on Sunday at the hospital in Wana, the main town in the region about three miles from the fighting, some berated the army for civilian casualties in the fighting.
According to local government officials in Wana and intelligence officials, about two dozen local people were killed in firing on five vehicles on Saturday. Gen. Shaukat Sultan said the vehicles were fired on because they were trying to escape a military cordon around the target area.
He said one bus, in which at least seven people were killed, was hit by a stray rocket fired by militants — although locals said it was hit by gunfire and rockets from a Pakistani helicopter.
Tribesman Zain Ullah said 12 of his relatives, including five women, died in the bus attack. Three of a dead cousin's children, ages 3 to 5, were injured, he said.
At the Wana hospital, dozens of relatives of victims were wailing and cursing the Pakistani army and President Gen. Pervez Musharraf — a key Washington ally — as more injured people arrived for treatment. They told doctors that they were targeted by the army.
"Pakistani soldiers are like beasts," said tribesman Mukhtar Wazir, as he looked on three wounded children receiving treatment. "See, these children are like flowers. Are they terrorists?"
"Musharraf is evil, (U.S. President George W.) Bush is Satan," said Wazir.
The military has refused to give updates of casualties until the current operation is complete.
On Friday, Sultan said 17 troops had been killed, most in the initial assault Tuesday. Only 26 militants have been confirmed killed. The actual toll is believed to be much higher on both sides.
Regional military commander Lt. Gen. Safdar Hussain said Saturday that most of the militants' radio conversations that were intercepted by the military were in Chechen and Uzbek, though some were in Arabic.
He would not be drawn on who the "high-value target" might be - only saying that the intensity of the resistance led him to believe he was probably still in the region. Pakistani officials speaking on condition of anonymity have previously said it was believed to be al-Zawahri.