Pakistan already has a sizeable military presence in North Waziristan, an estimated 28,000 to 30,000 troops, said defense analyst Zahid Hussain, whose book "The Scorpion's Tale" plots the rise of militancy in Pakistan.
Hussain said militants had been using North Waziristan essentially as a training base. This operation will establish the military's control across the territory and make it more difficult for militants to freely operate there. But, he warned, it won't be easy, and it will likely spark reprisals.
"It is going to be a long drawn-out war. It is not going to end soon," he said.
Even before the announcement, Pakistani jets early Sunday pounded insurgent hideouts in North Waziristan, targeting militants who carried out the Karachi airport siege, officials said. The military said 105 militants were killed in the strikes.
"There were confirmed reports of presence of foreign and local terrorists in these hideouts who were linked in planning the Karachi airport attack," the military said.
One of those killed was Abu Abdul Rehman al-Maani, believed to have helped orchestrate the airport siege, two intelligence officials said. They did not want to be identified because they were not authorized to speak to the media.
The area where the strikes occurred is remote and dangerous for journalists, making it difficult to independently verify the accounts.
Residents in North Waziristan said they were woken up after midnight to the sound of jets roaring overhead but said the strikes happened in a remote, mountainous area.
"All the family members gathered in the yard in fear," said one local resident, Tawab Khan, from the village of Boyapul, about eight kilometers (five miles) from where the airstrikes hit. "We could hear big bangs but they didn't come from very close to our area."
Already tens of thousands of residents of North Waziristan have fled the region due to earlier military airstrikes and out of fear of more. News of the operation will likely increase the exodus.
The military said most of the dead in the Sunday strikes were Uzbeks. Uzbek militants have long based themselves in Pakistan's northwestern tribal areas.
The Islamic Movement of Uzbekistan, along with the Pakistani Taliban, claimed responsibility for the airport attack in what was a rare instance of the group striking within Pakistan. The militant group was formed in 1991 to overthrow the Uzbek government and install an Islamic caliphate there but later expanded that goal to include all of Central Asia. The organization has attacked U.S. and NATO targets in Afghanistan.
Associated Press writers Riaz Khan in Peshawar and Zarar Khan in Islamabad contributed to this report.
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