There were conflicting casualty reports on the attack at the Khalis prison in Diyala province. Two provincial police officials and a medical official put the toll much higher, saying 51 inmates and 12 policemen were killed, while more than 200 inmates escaped. They spoke on condition of anonymity as they were not authorised to release the information.
Brig Gen Saad Maan Ibrahim, the Interior Ministry spokesman, told The Associated Press that a fight broke out first among the inmates of the prison and when guards went to investigate, they were overpowered and had their weapons taken. There are hundreds of inmates in the prison.
The town of Khalis is located about 80 kilometers north of Baghdad.
Jailbreaks are common in Iraq and usually a result of assaults from militants seeking to free their comrades in prison. The most stunning one was in mid-2013, when militants carried out a carefully orchestrated attack with mortar shells and suicide bombers on Iraq's infamous Abu Ghraib prison, freeing more than 500 inmates.
Meanwhile today, a car bomb exploded in Baghdad's central Karrada area, killing at least eight civilians and wounding 28, a police officer said.
Among the dead were Shiite pilgrims preparing for next week's major event commemorating the anniversary of the 8th century death of a revered religious figure, Imam Mousa al-Kazim. Thousands of pilgrims typically march to his shrine in northern Baghdad to commemorate his death.
No group immediately claimed responsibility for the bombing, but it bore the hallmarks of the Islamic State extremist group, which has carried near-daily attacks along with other Sunni militant groups against the Iraq's Shiite majority, government officials and security forces.
