"In the spirit of Eid al-Fitr, a day that marks the end of the holy month of Ramadan, the Iraqi government requested a special release board and worked with Multi-National Force-Iraq (MNF-I) to expedite the release of approximately 500 security detainees from Abu Ghraib," a military statement said.
Iraqi human rights ministry spokesman Hisham al-Suhaili said: "Five hundred and sixty-five detainees will be freed from Abu Ghraib on the occasion of Eid al-Fitr."
"These detainees were selected for release following a careful and thorough review of their files by a special Iraqi-led review board which determined they had not committed serious crimes against Iraqi forces, the citizens of Iraq or coalition forces," the US statement said.
Excluded were those convicted of violent crimes such as bombing, torture, kidnap or murder.
"This release is an acknowledgment by the Iraqi government and MNF-I of the importance of the holy month of Ramadan and Eid al-Fitr, the day of joy and thanksgiving," the statement added.
The US-run prison at Abu Ghraib was at the heart of photographs revealing the torture and abuse of Iraqi prisoners that seriously tarnished the reputation of the US military.
US soldier killed
In a separate incident, a US army soldier was killed by a roadside bomb in central Iraq, the military said on Tuesday, raising to at least 93 the number of American service members who died during October, the fourth deadliest month for the troops in the Iraq war.
The soldier, whose name was not released, was killed on Monday when a bomb exploded near his foot patrol in Haswah, 50km south of Baghdad, the military said.
October was the deadliest month
for US forces since January
The soldier was the seventh American service member killed on Monday in three separate attacks in Iraq.
All were victims of homemade bombs, which the military refers to as improvised explosive devices, or IEDs.
The deaths raised to at least 2026 the number of members of the US military who have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.
The US military death toll for October is now at least 93, the highest monthly total since January, when 106 American service members died - more than 30 of them in a
helicopter crash that was ruled an accident.
Only during two other months since the war began has the US military seen a higher toll: in November 2004, when 137 Americans were killed, and in April 2004, when 135 died.
In other parts of Iraq, three people were killed, including a policeman, when their patrol in al-Madain was attacked, south of Baghdad, Iraqi police sources said.
In Kirkuk, the city's police chief, Colonel Khatab Rash, and his driver were injured when a bomber targeted the chief's convoy as it passed through an area in the centre of the city.
Six Iraqi soldiers were injured when an explosive device was detonated targeting an Iraqi army patrol in northern Baquba city.
Iraqi election officials defied a new upsurge of violence and held a televised lottery on Tuesday to determine the order in which more than 200 parties will appear on ballot papers in the 15 December elections.
In the run-up to an election to choose the first full four-year parliament since the invasion of Iraq in March 2003, parties were hoping for a low number in the ballot, which would put their name near the top of the list, or something distinctive that would catch the attention of voters.
Parties hoped for a low ballot
number to catch voter attention
With 18 different ballot papers for 18 different provinces, preparations for the vote are complicated. Time is short because the process did not start until the results of the 15 October constitutional referendum were known.
In a televised spectacle that had the air of a game show, officials allocated numbers to the 225 parties and coalitions that registered for the ballot, starting from 501 - in order to avoid repeating numbers used at the last election that voters might already associate with parties.
With so many parties running, memorable numbers are highly prized so certain numbers such as 600 and 700 were not used.
The ruling United Alliance, which won nearly half of the votes at January elections, struck lucky with the number 555.