Associated Press In this handout photo from the U.S. Army, soldiers from the 10th Mountain Division (Light Infantry) participating in the Combined Joint Task Force Mountain's Operation Anaconda prepare to dig into fighting positions after a day of reacting to enemy fire Monday in Bagram, Afghanistan.

GARDEZ, Afghanistan - Airstrikes from American B-52 bombers shook the ground yesterday in some of the heaviest bombing of a six-day battle against tenacious al-Qaida fighters. The United States rushed in reinforcements and said 100 militants had been killed the previous day.

U.S. and allied Afghan soldiers were moving forward under al-Qaida fire, taking some ridges and caves in the mountainous region of eastern Afghanistan, said Maj. Bryan Hilfery, spokesman for the 10th Mountain Division.

U.S.-led infantry units have cleared out several cave hide-outs and al-Qaida compounds, including some where troops found AK-47 ammunition, medicine, night-vision devices and documents, including a Saudi identification card.

Hilfery said coalition forces killed at least 100 al-Qaida fighters Wednesday, but he had no word on new coalition casualties.

Eight American and three allied Afghan troops have died since Operation Anaconda began March 1.

Also, five international peacekeepers - two Germans and three Danes - were killed late Wednesday in Kabul while trying to defuse a Soviet-era missile left by the Taliban. Eight peacekeepers were injured in the first fatal accident since the force, which is separate from the U.S. military operation, was deployed to Kabul in December.

Throughout yesterday, thunderous blasts from B-52 bombers shook the mountains southwest of here. Dozens of Army Apache attack helicopters, armed with 30mm guns and Hellfire missiles, pounded targets in the narrow, craggy gorges.

The air bombardment, felt in Gardez at least 30 miles to the north, appeared heavier than in recent days as the United States accelerated efforts to crack the al-Qaida resistance.

Storm clouds moved in over Gardez in the afternoon and sandstorms whipped up, indicating possible snow in the mountains. Three Chinook helicopters flew into the key target area of Shah-e-Kot on supply missions under low cloud cover, but the worsening weather could hamper further action by the Apaches.

Afghan commander Ismail Khan said a U.S. special operations unit moved into the battle area Wednesday.

"There are 5,000 soldiers collecting in Shah-e-Kot for a final offensive on the al-Qaida to finish them off," Khan said. "It will be the final push."

Facing the allied soldiers is a force believed to be made up of Arab and other foreign fighters from al-Qaida, along with some of their Afghan Taliban allies. They are armed with mortars, small cannons, rocket-propelled grenades, shoulder-fired anti-aircraft missiles and Kalashnikov rifles.

Throughout the night Wednesday, U.S. transport helicopters shuttled between Bagram air base north of Kabul and the battle to the south, bringing in fresh supplies of food, fuel and ammunition.

In southern city of Kandahar, three U.S.-allied Afghan fighters were killed yesterday when one of them apparently accidentally tripped a booby trap at their own ammunition depot, a top Canadian officer said. Afghan forces said the men were moving a crate at the depot that they hoped to break down into firewood, said Lt. Col. Pat Stogran, commander of the 750 Canadians at the Kandahar air base.

The depot is about a mile south of the base.

Canadian troops went to help, Stogran said, but shrapnel and other ordnance flew over their heads. Detonations from the weapons depot continued into the evening and started a large brush fire.