The death toll from a fierce battle against militants by U.S. and Afghan forces in southeastern Afghanistan doubled to 40 on Thursday after troops found more bodies at the scene of clash, one of the deadliest since the fall of the Taliban in 2001.
The dead were a "mix of Taliban and anti-coalition militants," U.S. spokesman Col. James Yonts told The Associated Press. "These were well-trained, well-armed people ... not just a rogue group," Yonts said. "They didn't flee, they stood and fought."
"Important documents" found on the dead militants showed two were Chechens and one was Pakistani, said Ali Khali, spokesman for Zabul province's governor. He wouldn't give more details about the documents.
U.S. officials were still checking the dead fighters' identities.
The military had previously said about 20 militants died in the battle Tuesday in Zabul province's remote Dehchopan district, about 330 kilometers (205 miles) southwest of the capital, Kabul, when warplanes pounded militants fighting U.S. troops and Afghan police.
The toll rose to 40 - the highest from a single battle in nine months - after troops found more bodies, Yonts said.
A policeman also was killed, and six U.S. soldiers and five police were wounded.
Yonts said the wounded were in stable condition, and that four of the Americans had been taken to a U.S. military hospital in Germany.
Six insurgents and a village chief were detained.
The military said the fighting began when gunmen fired on a group of U.S. soldiers and Afghan police investigating the reported beating of an Afghan man.
However, provincial officials said rebels first attacked a checkpoint manned by police, who called for reinforcements. Afghan Interior Minister Ali Ahmad Jalali on Thursday gave another version, saying police were searching for three kidnapped doctors when they ran into trouble.
Officials said helicopters and other aircraft from the U.S.-led force then attacked the insurgents - a tactic that has inflicted heavy casualties on militants whenever they have been caught in the open.
Jalali said the doctors were found unharmed.
Zabul lies along the Afghan border with Pakistan, in an area where Taliban-led militants opposed to the government of U.S.-backed President Hamid Karzai have revived their three-year-old insurgency after a winter lull.
Jalali said at a news conference Thursday that more than 100 militants and at least 12 Afghan police had been killed in the past month, including the initial toll of 21 from the Zabul clash. Several civilians, as well as one U.S. and one Romanian soldier, have also died.
The latest fighting coincided with the installation of a new commander of the 18,000-strong U.S.-led coalition, who said Tuesday he would be "relentless" in battling the insurgency.
Lt. Gen. Karl Eikenberry said he would maintain the approach of bolstering Afghanistan's government while continuing the battle against militants and their leaders - including Osama bin Laden and Taliban chief Mullah Omar.
Yonts also welcomed the capture announced Wednesday in Pakistan of Abu Farraj al-Libbi, described as al-Qaida's No. 3 leader, but had no information on whether the Libyan was involved in organizing attacks in Afghanistan.
The number killed on Tuesday was the highest since Aug. 2 last year, when Afghan troops and U.S. warplanes killed up to 70 militants in a daylong battle in the southeastern province of Khost.
Khost is across from Pakistan's Waziristan area, where militants - including foreign fighters with al-Qaida links - are believed to have found refuge after the U.S. invasion of Afghanistan in 2001.
STEPHEN GRAHAM, Associated Press Writer
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