At the same time, the authority said it would take a more aggressive approach to hunting down leading figures in Saddam Hussein's regime still on its most-wanted list and other senior targets believed to be directing those fighting against the occupying forces.
"It is time for reconciliation, time for Iraqis to make common cause," Paul Bremer, the US administrator in Iraq, told a news conference, flanked by Adnan Pachachi, president of the Iraqi Governing Council, who praised the move.
"In a gesture to give impetus to those Iraqis who wish to reconcile with their countrymen, the coalition will permit some currently detained offenders to return to their homes and
families," Bremer said.
The change in policy follows last month's capture of Saddam and comes as Washington prepares to hand over power to an Iraqi government in June. It also coincides with persistent complaints from Iraqis that family members have been held without justification, or solely for being in the wrong place at the wrong time.
Human rights groups have also been pushing the US military to introduce a more transparent system for dealing with the hundreds of people they detain on raids who may be innocent.
Nine thousand detainees
An estimated 9000 security detainees are being held by US forces in Iraq and many more have been briefly detained and released since Saddam was ousted in April.
The first 100 prisoners will be freed on Thursday. Officials said they included 28 juveniles and were all male. Bremer said none of the prisoners involved was suspected of carrying out attacks against the coalition.
Among the Iraqi detainees to be
released are 28 juveniles
"This is not a programme for those with blood-stained hands. No person directly involved in the death or serious bodily harm to any human being will be released," he said.
Military officials said those to be released were mostly people detained for associating with suspected insurgents or carrying out low-level anti-occupation activities.
"When we've gone on raids, these were probably people who were in the room with insurgents when weapons were seized or they were engaged in some sort of suspicious activity," a senior military official said.
About 1200 security detainees were considered for the conditional release programme. Their cases were studied by a three-member military board, which approved 506 for release.
Those released must sign a form renouncing violence and must be seconded by a guarantor, such as a prominent community figure, religious leader or tribal chief, who will take responsibility for their conduct after release.
Released detainees must sign a
form "renouncing violence"
If they violate the conditions, they could be re-arrested.
Bremer said the new, softer approach would be accompanied by a crackdown on remaining die-hard insurgents, part of what a coalition official described as a "carrot and stick" approach.
As well as a $10 million reward already being offered for the capture of Izzat Ibrahim al-Duri, Saddam's chief deputy,
$1 million bounties have been put on the heads of 12 other members of the 55-most-wanted list who US forces say remain at large.
Bremer said a new programme offering up to $200,000 for information leading to the capture or death of about 15 people believed to be leading the resistance, but not among the 55, would also be introduced in the coming days.
"If they continue to fight, the coalition is prepared to capture or kill them and, I am convinced, the coming Iraqi government will be prepared to do the same," he said.