The United States has formally handed over control of a controversial prison to the Afghan government, despite a disagreement about the fate of some of the inmates.

More than 3,000 prisoners were transferred to Afghan officials in a small ceremony Monday at the Bagram prison. The transfer of authority over the prison and its inmates has been hailed by Afghan President Hamid Karzai as a victory for sovereignty

NATO said Sunday it had already handed over most of the detainees. However, the coalition said it has suspended additional transfers because of concerns about the intentions of the Afghan government to fulfill the terms of a memorandum of understanding signed in March.

It was not immediately clear what those concerns are, but they seem to have emerged after a meeting Saturday between President Karzai and General John Allen, the top commander of American and NATO forces in Afghanistan.

Another issue is how quickly the U.S. must hand over recently detained Afghans. Afghan officials insisted Sunday all detainees must be handed over within 72 hours.

The fate of around 50 foreigners, mostly from Pakistan, is not covered by the agreement.