Iraqi security forces have launched a search for dozens of al-Qaeda-linked inmates who escaped during an attack on a prison in the city of Tikrit that left at least 13 policemen dead.
The violence at the prison comes after al-Qaeda's Iraqi front group announced a campaign to regain territory and said it aimed to help its jailed members escape.
"Security forces were able to detain 33 of the escaped inmates, and there are still about 75 others" at large, Mohammed Hassan Attiya, the head of the Salaheddin provincial council security committee, told the AFP agencies on Friday, adding that "operations to pursue them are continuing."
"All of these inmates are Iraqi and members of the Al-Qaeda organisation," he said, and most have been sentenced to death.
Ahmed Abdul Jabbar, deputy governor of Salaheddin, told AFP on Friday by telephone that the Tikrit prison had been retaken from fighters who seized it initially on Thursday night, but that 83 prisoners escaped.
"We took control of the prison, and the gunmen handed over their weapons," a source in the Salaheddin police command said.
The prison, which housed several hundred inmates, many of whom are suspected of links with al-Qaeda, was attacked by unidentified armed men.
Accounts differed on the specifics of the jailbreak, but it appears armed men attacked from outside the prison, while inmates may have seized weapons from guards inside.
A police lieutenant-colonel said that a suicide bomber detonated a car bomb at the gate of the prison, after which it was assaulted by armed men.
A hospital official in Tikrit, the ancestral home of now-executed Iraqi ruler Saddam Hussein, said 10 police officers were killed and 34 wounded in the violence.
A curfew was imposed in the city, once home to now-executed former president Saddam Hussein.
Iraq's conflict has eased since its height in 2006-2007 when sectarian violence killed thousands.
But Sunni Islamists and an al-Qaeda affiliate still launch regular attacks, seeking to destabilise the country and undermine its Shia-led government.
Prison breaks are not uncommon in Iraq. Last September, 35 prisoners facing terrorism charges escaped via a sewage pipe from a temporary jail in the northern city of Mosul.