The U.S. military is holding about 500 juveniles suspected of being "unlawful enemy combatants" in detention centers in Iraq.

A total of 2,500 youths under the age of 18 have been detained for periods of up to a year or more since President Bush's anti-terrorism campaign began in 2002. Almost all those who have been detained are in Iraq. About 10 are currently being held in Afghanistan.

The disclosure has been made by the United States to a U.N. committee on children.

The ACLU and other civil liberties groups have denounced the practice as abhorrent. And they say it's in violation of U.S. treaty obligations.

The majority of those being held are believed to be 16 or 17 years old. The U.S. says the juveniles being held were helping insurgents.