Pakistani officials say the operation in the South Waziristan agency - situated along the border with Afghanistan - aims to bolster efforts by tribal leaders to capture suspected foreign militants believed hiding in the area.

Azam Khan, the top government representative in South Waziristan, says groups organized by the tribal elders have already captured and turned over 49 militant suspects. But he adds intelligence indicates at least 30 more possible terrorists in Waziristan. Mr. Khan declined to specify the nationalities of those captured, but says they include Afghans.

Recent reports say some of the militants may be members of al-Qaida, the group blamed for numerous terror attacks including suicide-hijackings against the United States in 2001. Top U.S. military officer General Richard Myers said earlier this month that al-Qaida leader Osama bin Laden is also likely hiding somewhere along the Pakistan-Afghan border.

Mr. Khan says Pakistan's new military operation has the support of the Waziristan population - a key factor as foreign fighters cannot stay hidden without help from the locals. "They cannot operate without the support of the masses," he says. "Just like fish [need] water, they have to move around with the people, and when the people rise against them, it's very difficult for them."

Mr. Khan says that while some Waziristan locals may have shown sympathy to the foreign militants in the past, much of that has since evaporated. He attributes this to a recent offer by Pakistani President Pervez Musharraf, promising leniency toward those who admit to sheltering foreign fighters, so long as they turn the militants into the authorities.

"That's why now the locals here are rallying against them," says Mr. Khan. "[The tribal leaders say] that, look, this is a very fair offer from the government, that's the most the government can do, and if you're not taking up this offer, then you are up to something no good."