Major Afghan offensive launched
U.S. soldiers rest outside a house in a village in eastern Afghanistan.
Barbara Starr reports from Firebase Cantamount, deep inside Afghanistan
(CNN) -- The U.S. military has launched a major ground operation in Afghanistan in an effort to eliminate the remnants of al Qaeda and the Taliban regime overthrown in 2001.
Military spokesman Lt. Col. Bryan Hilferty described "Operation Avalanche", which began over the weekend, as the largest ground operation yet in Afghanistan.
He said the operation would focus on areas where international troops and aid workers have been hit by terrorist cells.
"We're going to operate simultaneously throughout the entire eastern and southern part of the country so we get inside the decision cycle; so we hit them before they can hit innocent men, women and children," Hilferty said.
Between 2,000 and 11,500 soldiers will be dispatched in east and south Afghanistan to go after Taliban and al Qaeda militants, he said.
"The terrorists are going into their winter campaigning season where they don't campaign as much," he said "We're going to make sure that we get them before they get a chance to hunker down. "
Hilferty said Operation Avalanche comes as Operation Mountain Resolve, carried out in the snowy peaks of eastern Afghanistan, ends.
But the new offensive was marred by a botched weekend operation in which U.S. military aircraft appear to have accidentally killed nine children in an airstrike on the east-central Afghanistan village of Petaw.
The children and a still unidentified man were killed in an attack that targeted a suspected Taliban terrorist. (Full story)
On Monday, the military reiterated its regrets and offered humanitarian aid to the village located between Kabul and Kandahar about 53 miles (85 kilometers) southwest of Ghazni in the Makur district.
Hilferty said the villagers accepted gifts of blankets, clothing, food and toys, despite their sadness over the deaths of the children.
Military officials said the airstrike was carefully orchestrated to target one man and avoid civilian casualties, but the children and the body of a still unidentified man were found after the attack.
"We accept blame," Hilferty said. "We offer our condolences to the village, but I will tell you the surveillance video shows no children there. But we're not trying to avoid blame in this."
He said an investigation will clarify what happened to the children.
"The biggest thing is we want to express our condolences no matter what happened," Hilferty said.
Additionally, he said witness accounts from villagers indicated that the man who was killed was not the intended target, but DNA tests on the body have not been concluded.
"It could be a different person but still be a very bad person, so we can't come to any conclusion yet until the investigation," Hilferty said.
The intended target is believed to have been responsible for killing two contractors working on the Kabul-Kandahar-Herat ring road in Oruzgun or Zabol province in October.
Meanwhile, a Pakistani engineer working in Afghanistan for the U.S. government was killed Monday and another was seriously wounded when their vehicle came under automatic weapons fire, a company executive told CNN. (Full story)
And on Saturday at least 15 people were wounded after a bomb attached to a bicycle exploded in Kandahar's main square. (Bicycle bomb injures 15)