In Baghdad, 44 prisoners were released on Sunday from an Iraqi National Guard base in the western Amiriya district in the presence of a tribal leader who acted as their guarantor.
A big black bus pulled into the base as Shaikh Hisham al-Dulaimi and other Sunni Muslim tribal elders lined up to greet them.
"Long live Falluja!" shouted Ahmad Kurdi, 21, from the bus, hailing the Sunni anti-occupation bastion, west of the capital.
Kurdi said he was held in Baghdad's notorious Abu Gharib prison with his brother for 45 days after they were arrested by US troops at their home in Amiriya.
Kurdi has two other brothers in jail, one of whom has been held for nine months in Camp Bucca, outside the southern port city of Umm Qasr.
He says he still does not know why he was arrested.
Neither does Mahmud Dia, 17, who was arrested in the southern city of Nasiriya and held for 15 months in Abu Gharib.
"I am not with the insurgents and do not even own a weapon, they just me picked up from the street like that," he said.
A young man interrupted to recount "the injustice he was subjected to".
Ali Muhammad Alwan, 17, said he was held in Abu Gharib for 14 months after getting into a fight with a Kuwaiti translator working for US troops, who provoked him by insulting his mother in a Baghdad restaurant.
"One of my rib bones is broken, they beat the hell out of me every time they interrogated me, it felt like dying a hundred times"
Ali Muhammad Alwan, 17,
"One of my rib bones is broken, they beat the hell out of me every time they interrogated me, it felt like dying a hundred times," said Alwan angrily.
Shaikh Muhammad al-Zubaidi, 38, said he was jailed for a month in Abu Gharib after US troops and Iraqi police barged into his home in Baghdad's southern Dura district one night.
"They found a newspaper in my house that had an article about Falluja and they started questioning me about that," he said.
US Captain Bill Meredith admitted that many mistakes were made, including arrests based on false information, but said procedures had been changed to rectify the problems.
"We do not want to do things that create more enemies, we do not want to put one guy in jail and have four spring up in his place. That has been something difficult for us to learn," said Meredith, of the 1st Cavalry Division.
In April, hundreds of photographs and reams of video footage surfaced, depicting the horrors of abuse committed by US troops late last year in Abu Gharib.
Since then, the US military has released hundreds of prisoners and tried to improve conditions for the remaining detainees.
But all prisoners are still held without trial.