The American military stepped up efforts to find Usama bin Laden (search) and destroy his Al Qaeda (search) and Taliban (search) supporters, announcing Saturday a major new sweep across lawless southern and eastern Afghanistan involving thousands of troops.
The military insisted their net will eventually close on the Al Qaeda leader, who has vanished since melting into the Afghan mountains months after the Sept. 11 attacks on the United States.
A spokesman said the new operation also will prepare the way for reconstruction in impoverished provinces along the Pakistani border — a reward the military hopes will loosen villagers' tongues.
"It's certainly about more than one person," Lt. Col. Bryan Hilferty said. "We do have confidence, though, and the leaders of Al Qaeda and the leader of the Taliban need to be brought to justice — and they will be."
Afghan officials hailed the new push and said their forces were fully involved.
"They are trying to eliminate the enemies of Afghanistan and the enemies of the world," said Hilalludin Hilal, the deputy interior minister in Kabul.
American commanders have vowed to crush militants and snare bin Laden as well as Taliban leader Mullah Mohammed Omar (search) this year, with a combination of military might and desperately needed aid.
But they face enemies — estimated at less than 1,000 active fighters by a top U.S. general this week — that present no easy target, moving in small groups and preying on civilians, including aid workers and minor government officials, as well as military targets.
Hilferty said the new operation, which began Sunday, would continue tactics already employed by the 13,500 U.S.-led troops tracking militants more than two years after the fall of the Taliban.
That includes frontier patrols, house-by-house searches and surprise checkpoints and air assaults.
"We believe this will help bring the heads of the terrorist organizations to justice, by continuing placing pressure on them," Hilferty said.
Troops carried out an air assault in southern Afghanistan on Thursday, but Hilferty would not give details, saying soldiers were still on the ground Saturday.
He declined to say how many soldiers would be involved in the new operation, but said they would have air support "24 hours a day, circling overhead ready to assist."
An Afghan army commander in southern Kandahar province, Haji Granai, told The Associated Press that U.S. aircraft killed 12 suspected Taliban in a pickup truck there Thursday.
Granai said the planes struck in Maruf (search) district, some 160 miles east of Kandahar city, where suspected Taliban killed seven Afghan soldiers in a March 3 raid on a border post.
The U.S. military had no immediate comment.
Hilferty played down suggestions by Washington officials that the military was embarking on a "spring offensive."
"If it continues past March 21, I assume it will be a spring operation. But a spring offensive is what the media have been calling for, not us," he said.
But there are signs that forces were adding muscle.
The number of U.S. soldiers has risen by some 2,500 since late last year, an increase officials attributed to a new headquarters in Kabul and new security teams placed in provincial capitals.
But the military has not denied reports that members of Task Force 121 (search), a crack unit of special forces and CIA agents who helped corner Saddam Hussein (search), have arrived from Iraq to beef up the search for bin Laden.
The new U.S. offensive is also supposed to safeguard landmark Afghan elections slated for June, when U.S.-backed President Hamid Karzai (search) is expected to secure a new term.
More than 140 people have died in violence already this year, underlining security fears ahead of the vote.
Lt. Gen. David Barno, the top American commander in Afghanistan, has said his soldiers are engaged in a "hammer-and-anvil" strategy along with Pakistani forces on the other side of the border.
Some 70,000 Pakistani troops have moved into semiautonomous tribal regions in an effort to take away maneuver room for Al Qaeda and Taliban fugitives believed to have taken refuge there.
On Saturday, tribal elders in South Waziristan gave a 24-hour deadline to a tribe accused of sheltering terrorists to hand over the fugitives or expect an armed force of 600 men to search the area.