Thousands of Iraqis held without charge by the United States on suspicion of links to insurgents or militants are being freed by this summer because there is little or no evidence against them.

Their release comes as the U.S. prepares to turn over its detention system to the fledgling Iraqi government by early 2010. In the six years since the war began, the military ultimately detained some 100,000 suspects, many of whom were picked up in U.S.-led raids during a raging, bloody insurgency that has since died down.

The effort to do justice for those wrongly held to begin with, some for years, also runs the risk of releasing extremists who could be a threat to fragile Iraqi security.

As part of an agreement between the two countries that took effect Jan. 1, Iraqi authorities have begun reviewing the cases of the detainees to decide whether to free them or press charges. About 13,300 remain behind barbed wire in U.S. custody in Iraq.

But Iraqi judges have issued detention orders to prosecute only 129 of the 2,120 cases they have finished reviewing so far this year -- or about 6 percent, according to U.S. military data. As of Thursday, 1,991 detainees had been freed since Jan. 1.

An Associated Press reporter embedded for two days at Camp Bucca, the largest U.S. detention facility in Iraq, and talked with military officials about preparations to shut it down.

"God willing, God willing," said Layla Rasheed after learning that her son, a former government worker from Baghdad, was likely to be released. "He doesn't have anything to do with terrorists. I don't know why he was picked up."

The military also expects to release another 600 detainees by the end of March, a spokesman said.

The U.S. detention policy has been unpopular in a country where many feel that thousands have been detained without cause, and where the Abu Ghraib prison abuse scandal will be remembered for a long time.

Iraq's biggest Sunni parliamentary bloc has called for the release of virtually all detainees, arguing that even those who were militants no longer pose a threat because so many Sunni groups have abandoned the insurgency.

"It's very easy to go back and say, 'Well, you rounded up all these innocent people.' Well, innocence has different shades," Brig. Gen. David Quantock, commander of the U.S. detention system in Iraq, said in an interview this week.

"It's not like we have a choice -- it is prosecute or release. So it's a huge undertaking right now to try to find as much evidence as we can. We're not going after all of them, we're going after a certain amount."

One Camp Bucca imam said the majority of detainees are ready to forgive once they are released -- even if they are angry and confused after being held so long.

"Some of them have decided to go outside Iraq to change," said the imam, who identified himself only as Sheik Abdul-Sattar. "Some can say, we can forgive everyone. The majority are like that. The extremists speak of revenge."

Many detainees locked up at Guantanamo were innocent men swept up by U.S. forces unable to distinguish enemies from noncombatants, a former Bush administration official said Thursday. "There are still innocent people there," Lawrence B. Wilkerson, a Republican who was chief of staff to then-Secretary of State Colin Powell, told The Associated Press. "Some have been there six or seven years."

Wilkerson, who first made the assertions in an Internet posting on Tuesday, told the AP he learned from briefings and by communicating with military commanders that the U.S. soon realized many Guantanamo detainees were innocent but nevertheless held them in hopes they could provide information for a "mosaic" of intelligence.

"It did not matter if a detainee were innocent. Indeed, because he lived in Afghanistan and was captured on or near the battle area, he must know something of importance," Wilkerson wrote in the blog. He said intelligence analysts hoped to gather "sufficient information about a village, a region, or a group of individuals, that dots could be connected and terrorists or their plots could be identified."