Bagram, Afghanistan ? Backed by U.S. air power, some 1,000 coalition troops spread out Friday into mountainous eastern Afghanistan to find and fight suspected al-Qaida or Taliban soldiers who had fired on an Australian patrol.

Brig. Roger Lane, the top British commander in Afghanistan, said the targeted assembly of suspected al-Qaida or Taliban fighters in Paktia province was “a substantial enemy force,” though he declined to give a number.

A group of British Royal Marines departs for Operation Condor at Bagram airbase, some 31 miles northeast of Kabul. Coalition forces launched a new offensive Friday, hunting al-Qaida members in eastern Afghanistan.

U.S. military spokesman Maj. Bryan Hilferty said later the coalition believed there were about 100 al-Qaida or Taliban fighters in the area.

No coalition fighters were hurt during Thursday’s attack on an Australian special forces patrol, Lane said, though some suspected al-Qaida and Taliban soldiers were killed.

“Our ability to respond rapidly to such attacks will serve as a reminder that the coalition will not tolerate such activity and we will hunt the terrorists relentlessly,” Lane said from Bagram, the main allied base north of Kabul.

The new mission begun Friday involved mostly British troops and was named Operation Condor. All three missions the British have led since coming to Afghanistan in April have been named for birds; the first was Operation Ptarmigan, after a Scottish mountain bird, and the second was Operation Snipe, which the British define as a variety of slender-billed birds.

In Washington, Defense Secretary Donald Rumsfeld said: “There are now and there will be in the future a variety of efforts where coalition forces will be conducting sweeps through areas that we have reason to believe could or might or do have varying concentrations of al-Qaida or Taliban.”

Rumsfeld said this frequently was done in cooperation with Pakistani forces “so the possibility of escape is reduced.”

Hilferty said American forces had not deployed ground forces, but were backing the British-led mission with air power. He said AC-130s had been called in to help the Australians on Thursday night, opening fire on their attackers.

Meanwhile, local security officials said at least 10 Afghan tribesmen feuding over land were killed in eastern Afghanistan when U.S. planes bombarded their positions after shooting erupted on the ground.