Sixty-five detainees have been released from Afghanistan's Bagram detention centre, local officials say, despite strong protests by the US.
Washington argues the move is dangerous, saying it has evidence the men were responsible for carrying out attacks on Nato and Afghan troops.
But Kabul insists there is not enough evidence against the detainees.
Hundreds of prisoners at Bagram jail have been freed since it was put under Afghan control in March last year.
The detainees began to emerge from the gates of prison in groups of half a dozen or so on Thursday morning, the BBC's Kabul correspondent reports.
Some were reportedly laughing and smiling as they boarded a bus and taxis to leave the facility.
The Americans believe the releases violate the Bagram transfer agreement because evidence against the men has not been 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 US says there also is other incriminating information from mobile phones, and details of interviews with suspects including confessions.
The release marks 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 Afghan President Hamid Karzai, who has long campaigned against Bagram detention centre.
The facility, which houses mainly Taliban and other insurgents captured by Western military forces, has also been at the centre of a number of prisoner abuse allegations.