The Bush administration suggested Tuesday that prisons in Iraq where hundreds of detainees apparently were abused may not have been under the control of the central government in Baghdad.

And, while the central government, with U.S. help, is trying to take charge of these "nominal prisons" the problem has not been solved, State Department spokesman Adam Ereli said.

"We and the Iraqi government continue to have concern about the way prisoners are treated," the spokesman said.

Ereli's statement acknowledged weakness in the Iraqi government, but also credited it with trying to address a problem that undercuts the administration's case that reform is taking hold since the toppling of President Saddam Hussein.

"We are working with the Iraqi government to provide advice and technical assistance" to correct the prison situation, the U.S. spokesman said.

U.S. Ambassador Zalmay Khalilzad said earlier this month that at least 120 abused prisoners were found in two detention facilities run by the Shiite-led Interior Ministry.

Even before then, Sunni Arabs had complained about abuse and torture by Interior Ministry security forces.

The U.S. military said Sunday it would not hand over detention facilities or individual detainees to Iraqi officials until they have demonstrated higher standards of care.