The U.S. military said Thursday it returned last prison in Iraq to local authorities, thus closing a dark chapter of the war began in March 2003, punctuated by thousands of arbitrary detentions and serious abuses.

At a ceremony held at Camp Cropper, a detention facility near Baghdad airport, the U.S. military officials have told their Iraqi counterparts a giant symbolic key. They expressed confidence in their treatment of prisoners under Iraqi authority. They also acknowledged the past mistakes, illustrated by the abuses at Abu Ghraib prison near Baghdad, where detainees were abused and humiliated by their American jailers. Revealed in 2004, these incidents had sparked outrage in Iraq and around the world and had probably helped fuel the insurgency.

“To be perfectly honest, we have learned from our experiences here,” said the press spokesman of the U.S. military in Iraq, Gen. Stephen Lanza. “We learned from our experiences in terms of management of inmates and our inability to prepare ourselves for what we were going to meet,” he added.

The prison still exist, but changes name

In over seven years, nearly 90,000 people have been detained by U.S. forces on suspicion of being Islamist insurgents or Shiite militiamen. Never charged, they have spent months or years in prison at Camp Cropper and Camp Bucca, a vast complex located in the south, near the Kuwaiti border, and closed last year. Many journalists were also detained for months without knowing why.

The Camp Cropper is still open for at least two years and Iraqi custody, will now be known as Camp Al Karkh. The United States relinquished their right to detain Iraqis under the bilateral security treaty in 2008, which provides the complete withdrawal of U.S. forces by the end of next year.