The MH-47 Chinook helicopter -- with 16 people on board who all died in the crash -- had gone into the mountains Tuesday to extract the soldiers who are now missing. The team on the ground has been unaccounted for since the chopper was downed, US military spokesman Lt. Col. Jerry O'Hara said.
A purported Taliban spokesman, Mullah Latif Hakimi, meanwhile, claimed the rebels had captured a US soldier in the area, near the town of Asadabad, close to the Pakistani border.
"One high-ranking American has been captured in fighting in the same area as the helicopter went down," he told The Associated Press. "I won't give you any more details now."
Reacting to the claim, O'Hara said, "We have no proof or evidence indicating anything other than the soldiers are missing."
Hakimi, who also claimed that the insurgents shot down the helicopter, often calls news organizations to take responsibility for attacks, often with information that proves exaggerated or untrue. His exact tie to the Taliban leadership is not clear.
O'Hara said US forces were using "every available asset" to search for the missing troops. "Until we find our guys, they are still listed as unaccounted for and everything we got in that area is oriented on finding the missing men," he said.
The loss of the 16 troops on the chopper was the deadliest single blow to American forces who ousted the Taliban in 2001 for harboring al-Qaeda and are now fighting an escalating insurgency. The bodies of the 16 have been recovered and troops Friday were trying to identify the remains, the military said.
Rescuers -- struggling against stormy weather, insurgents and the rugged terrain -- reached the crash site Thursday, about 36 hours after the chopper went down in high mountains near the town of Asadabad.
The rescue team was still there Friday, recovering parts of the chopper, US military spokeswoman Sgt. Marina Evans said.
At the Pentagon in Washington, Lt. Gen. James Conway, director of operations for the Joint Chiefs of Staff, said it appears an unguided rocket-propelled grenade hit the chopper. He called it "a pretty lucky shot against a helicopter."
He said it appeared the troops on board died during the crash and not during fighting on the ground afterward.
Only eight months ago, Afghan and US officials were hailing a relatively peaceful presidential election as a sign that the Taliban rebellion was finished.
But remnants of the former regime have stepped up attacks, and there are disturbing signs that foreign fighters including some linked to al-Qaeda -- might be making a new push to sow an Iraq-style insurgency.
Afghan officials say the fighters have used the porous border with Pakistan to enter the country, and have called on the Pakistani government do more to stop them.
The loss of the helicopter follows three months of unprecedented fighting that has killed about 465 suspected insurgents, 43 Afghan police and soldiers, 125 civilians, and 45 US troops, including the 16 killed in Tuesday's crash.
The crash was the second of a Chinook helicopter in Afghanistan this year. On April 6, 15 US service members and three American civilians were killed when their chopper went down in a sandstorm while returning to the main US base at Bagram.
The dead in this week's crash comprised seven soldiers from the 3rd Battalion, 160th Special Operations Aviation Regiment (Airborne), Hunter Army Airfield, Ga., one from the 160th Special Operations Aviation Regiment (Airborne), Fort Campbell, Ky., and eight Navy SEALs assigned to units in Norfolk, Va., and San Diego, the US military said in a statement.
"The remains are being identified. The service members' names will be released once their next-of-kin have been notified," the statement said.
Associated Press reporter John J Lumpkin in Washington contributed to this report.