Iraqi forces on Friday hunted for dozens of convicted Al-Qaeda militants who escaped during a prison uprising north of Baghdad that left 16 security force members dead, the interior ministry said.

The violence at the prison comes after Al-Qaeda's Iraq front group announced a campaign to regain territory and said it aimed to help its jailed members escape.

Out of 303 prisoners in the prison in Tikrit, the ancestral home of now-executed Iraqi dictator Saddam Hussein, "47 of them are members of the terrorist organisation called the Islamic State of Iraq, and they have been sentenced to death," the interior ministry said in a statement.

A total of 102 prisoners managed to escape during the uprising, among them the 47 members of the Al-Qaeda front group, the ministry statement said.

"Salaheddin police managed to kill four of them and to arrest 23 fugitives, but the whereabouts of the... others is still unknown," the statement said, adding that 16 security force personnel were killed in clashes.

The ministry said the violence began when inmates at the prison killed an officer and took his weapon and then seized other weapons from an armoury and used inmates as human shields to aid their escape.

While the interior ministry said the violence was due to an uprising from within the prison, other sources reported that militants used explosives to breach the facility.

A police lieutenant colonel said Thursday that a suicide bomber detonated a car bomb at the gate of the prison, after which it was assaulted by gunmen.

A traffic police lieutenant colonel who was near the scene at the time said militants blew up part of the prison fence.

Journalists from outside Tikrit were prevented by security forces from entering the city.

The tactic of using explosives to breach the perimeter followed by an attack by gunmen is reminiscent of attacks in July and August.

Gunmen attempted to use bombs to breach a prison gate in Taji, north of Baghdad, on August 1, after using similar tactics on the counter-terrorism directorate in the capital the day before in an attack the interior ministry said was an attempt to free inmates.

The interior ministry statement said that the head of Salaheddin police, Staff Major General Abdul Karim al-Khazraji had been dismissed, and will be temporarily replaced by Staff Major General Ghanim al-Qurayshi.

A curfew has been imposed in Tikrit until fugitives are found, it added.

The Islamic State of Iraq said in July that it was launching a "new military campaign aimed at recovering territory."

An earlier message posted on jihadist forums said the ISI would begin targeting judges and prosecutors, and try to help its prisoners break out.

While insurgents opposed to the Baghdad government are regarded as weaker than in past years, they have shown they can strike at even the most heavily protected sites in Iraq.

In addition to the prison in Taji and the counter-terrorism directorate, targets in recent months have included a police station, a military base and an entrance to Baghdad's heavily fortified Green Zone, where the government is headquartered.