Abu Ghraib has changed drastically since this photo was taken in 2004
Inmates started a fire and clashed with guards during a riot at Iraq's Abu Ghraib prison.
Officials said the trouble began while warders were carrying out a search for banned drugs and other items.
Shots were fired, and US helicopters along with Iraqi troops were brought in to help defuse the situation.
Abu Ghraib became notorious for the abuse of detainees by US forces in 2004, but has since re-opened under a new name, Baghdad Central Prison.
The unrest began on Thursday, when three inmates started a fire in their cell "and tried to overpower guards in an apparent escape attempt", US military spokesman Master Sgt Nicholas Conner said.
A local council member for the Abu Ghraib district, which is in western Baghdad, said the inmates had set fire to mattresses while the prison was being searched for mobile phones and banned drugs.
Witnesses reported hearing shots being fired from within the prison.
The Iraqi military and police were called, while US helicopters monitored areas outside the prison, Master Sgt Conner said.
The violence was said to have flared again on Friday, but the US military was not called out and the prison is now reported to be under the authorities' control.
Some Iraqi media said there had been fatalities, but Master Sgt Conner said the Iraqi authorities reported that three guards and three inmates had been injured.
It was not clear what sparked the incident, although some reports said inmates were unhappy about jail conditions.
Abu Ghraib re-opened as Baghdad Central Prison last February, with upgraded facilities and amenities. Iraqi's justice ministry billed it as a model prison.
But the jail has a grim history. It was used as a major centre for torture and execution for thousands of people during the regime of Saddam Hussein.
In 2004, photographs emerged that showed US guards abusing and humiliating their prisoners there.