Afghanistan has released 65 prisoners from Bagram prison near the capital Kabul - a move condemned by the United States.
The US embassy in Kabul said some of those released were responsible for the deaths of Afghan civilians, and Afghan and coalition troops.
It wanted many of them to face trial in Afghan courts.
Kabul, which took over control of Bagram last year, insists there is not enough evidence against the detainees.
President Hamid Karzai has described the prison as a "Taliban-making factory".
The BBC reports the detainees began to emerge from the prison gates in groups of half a dozen or so on Thursday morning.
The Parwan Detention Facility is about 45km north of Kabul.
In a statement, the US embassy said:
"The Government of Afghanistan's decision to release 65 detainees from the Parwan Detention Center is deeply regrettable.
"We requested a thorough review of each case. Instead, the evidence against them was never seriously considered."
Washington says one of the men was captured after being wounded during an attack on Afghan forces.
Others were reportedly arrested carrying weapons including shotguns, assault rifles and rocket-propelled grenade-launchers and bomb-making equipment.
The embassy said: "The Afghan government bears responsibility for the results of its decision."
US forces in Afghanistan said that some of the other prisoners released since Afghanistan took over control of the prison have already ''returned to the fight''.
A BBC correspondent said the decision to release the prisoners was a political one taken personally by President Hamid Karzai. Eighty six others were freed in December.
Mr Karzai said the issue is of no concern to the United States.