WASHINGTON, Dec 5: A 900-kg bomb from a B-52 killed three US special forces troops and five Afghan allies north of Kandahar on Wednesday. At least 40 others, including Hamid Karzai, named to head a new government, were injured.

Hamid Karzai was meeting soldiers of the US special forces when the satellite-guided bomb struck near their position, a US defence official said.

The Pakhtoon anti-taliban leader was lightly injured by debris from the blast. karzai suffered “scrapes and bruises, not from the bomb but from dirt and gravel and stuff”, the official said.

It was the worst casualty toll suffered by US forces in a single incident since the airstrikes in Afghanistan began on Oct 7, and marked the second time that US warplanes had mistakenly struck their own forces.

In a previous “friendly fire” incident, five US troops were wounded by a 220-kg bomb at the Qila-i-Jangi prison on Nov 25.

The American casualties were not immediately identified pending notification of next of kin, the Pentagon said.

President George W. Bush offered “his condolences to the families and loved ones who were affected by this morning’s accident. He regrets the loss of life and wishes the injured a full and speedy recovery,” said White House spokesman Ari Fleischer.

Some of the Americans and about 20 Afghan opposition fighters were flown by helicopter to a marine base south of Kandahar for initial medical treatment, Marine Captain Stuart Upton told reporters at the base, Rhino Forward Operating Base.

Most were transferred from there to other facilities for further medical treatment, he said.

Bryan Whitman, a Pentagon spokesman, said the US forces involved were “special forces who are working in support of Afghan opposition groups in the vicinity of Kandahar”.

Afghan opposition forces operating north of Kandahar belong to Karzai, one of the first tribal leaders to take up arms against the Taliban in the south.—AFP