Dramatic video has been released of U-S helicopters in action over mountains in the Gardez region of eastern Afghanistan.
There, U-S troops are locked in combat against al-Qaida and Taliban forces, who are holed up in mountains and caves in the region, situated about 75 miles (121 kilometres) south of Kabul.
U-S and their allied Afghan forces have met far stiffer resistance than expected in their mission to wipe out Taliban and al-Qaida troops, according to commanders and soldiers.
At least eight Americans have died in the fighting since Saturday and about 40 have been wounded.
The operation, code-named Anaconda, had originally called for a small detachment of U-S Special Forces, working with local Afghan commander General Zia Lodin, to enter the town of Sirkankel to flush out suspected al-Qaida and foreign Taliban forces.
Sirkankel is about 25 miles (40 kilometres) south of Gardez.
But many U-S and Afghan troops were pinned down for hours by robust resistance from the Taliban and al-Qaida.