At least three dozen people were killed and 40 inmates escaped in a prison break north of the Iraqi capital, Baghdad, officials said Saturday.
Iraq's Interior Ministry said six police officers and 30 prisoners were killed in the riot at the Khalis prison. But other officials put the death toll much higher, reporting 12 policemen and at least 50 inmates killed.
Officials said a fight broke out among the inmates, and when guards came to intervene, the prisoners overpowered them and took their weapons.
Islamic State militants claimed responsibility for the prison break and gave their own version of events in a statement posted on jihadist websites. The group said it set off multiple explosions outside the prison in a coordinated operation with inmates on the inside. Some 30 IS members were among those who escaped, according to the statement.
Iraqi officials said some of the escapees had been jailed on terrorism charges.
Jailbreaks are common in Iraq, which has spent the past year fighting an insurgency by Islamic State militants.
Also Saturday, a car bomb in Baghdad killed at least seven people and wounded at least 14 others, according to police and other sources. News reports indicated the attack targeted Shi'ite pilgrims.
The French news agency AFP said the Islamic State group claimed responsibility for the car bombing.
In other news, the U.S.-led coalition that's fighting Islamic State militants said it had conducted 15 airstrikes in Syria and 13 in Iraq since Friday. A statement said the airstrikes had hit 10 IS tactical units and had destroyed nine fighting positions near al-Hasakah in Syria, and had targeted sites in Iraq near Baiji, Fallujah, Tal Afar, Sinjar, Mosul and al-Assad.