Sixty-five detainees have been released from Afghanistan's high security Bagram detention centre, a move condemned by the US as "deeply regrettable".
The US embassy in Kabul said some of those released were responsible for the deaths of Afghan civilians, and Afghan and coalition troops.
Kabul, which took over control of Bagram last year, insists there is not enough evidence against the detainees.
President Hamid Karzai has described the jail as a "Taliban-making factory".
'Never considered' The detainees began to emerge from the prison gates in groups of half a dozen or so on Thursday morning, the BBC's David Loyn in Kabul reports.
Some were laughing and smiling as they boarded a bus and taxis to leave the facility, which is now called the Parwan Detention Facility and is about 45km (28 miles) north of Kabul.
Our correspondent spoke to one of the freed men, Nurullah, who US forces accuse of being a Taliban commander responsible for operations that resulted in the death of a US soldier in Logar province.
Sitting in a cafe, eating his first meal in freedom since his capture last March, Nurullah denied the allegation, saying he had been training as a builder.
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."
It said: "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."
The US forces in Afghanistan said that some of the other prisoners released since the Afghans took over control of the prison had "already returned to the fight. Additional released detainees may continue to fill the ranks of the insurgency".
The releases mark a new low in relations between Afghanistan and the US forces in the country, our correspondent says.
He adds that the decision is a political one taken personally by President Karzai.
The facility, which houses mainly Taliban and other insurgents captured by Western military forces, has been at the centre of a number of prisoner abuse allegations.
The BBC's Yalda Hakim was recently allowed unprecedented access.