The U.S. command in eastern Afghanistan is confirming that U.S. and Afghan forces are conducting an offensive against insurgents in the rugged Tora Bora region. VOA's Al Pessin reports from the Pentagon.

A spokeswoman for the coalition task force in the region says the operation involves several hundred U.S. and Afghan troops and has been going on for a few days. Captain Vanessa Bowman says the force is targeting insurgent support bases and training sites near the Afghan-Pakistan border.

She says there have been no coalition casualties, and "no substantiated reports" of civilian casualties. Coalition and NATO forces have been criticized for accidentally killing too many Afghan civilians, but Captain Bowman says targets for the current operation were chosen, in part, with a view to avoiding civilian casualties.

Bowman could not confirm reports of a parallel, coordinated Pakistani operation on its side of the border.

"I do not have information on Pakistan operations," said Bowman. "All I know is it is an operation between the Afghan and U.S. forces within Afghanistan to disrupt the militants there in the Tora Bora region."

Bryan Whitman (file photo)

At the Pentagon, spokesman Bryan Whitman described this effort as part of the normal "peaks and valleys" of what he called "aggressive offensive operations" by coalition forces in Afghanistan. And he also could not say whether Pakistani forces are conducting a parallel operation.

"Particularly along the border region, our cooperation with Pakistan is very good," said Whitman. "And we have mechanisms for ensuring that we exercise the necessary control measures to understand what is occurring on each side of the border because, as you can imagine, that is important."

Whitman said such operations are driven by intelligence, but neither spokesman could say whether senior Taleban or al-Qaida leaders were the targets. The insurgent leadership is believed to be hiding in the Afghanistan-Pakistan border region, and has been headquartered in Tora Bora in the past.

The operation is being conducted by what is called Combined Joint Task Force 82, the remnants of the U.S.-led coalition that invaded Afghanistan in 2001. The force is responsible for counter-insurgency operations in Afghanistan, particularly in the east, while NATO forces now have general security responsibility throughout the country.