U.S. forces have launched a large-scale operation in southeastern Afghanistan aimed at Usama bin Laden's Al Qaeda network, a U.S. Army spokesman said Monday.

Operation Champion Strike began a few days ago and is centered in the Bermel valley near the town of Shkin about 150 miles south of the capital Kabul, Maj. Richard T. Patterson said.

Shkin is located in Paktika province on the border with Pakistan.

Because Champion Strike is an ongoing operation, Patterson said he could provide only limited details. He would not say when Champion Strike was launched or when it would end.

However, Patterson said there has been one firefight involving U.S. soldiers since the operation began. There were no U.S. casualties nor deaths among the enemy, he said.

Soldiers taking part in the operation have detained a number of people, Patterson said.

U.S. forces have also seized weapons caches, which included assault weapons, land mines and rockets, Patterson said without elaboration.