A prison break in Saddam Hussein's hometown in which dozens of Al Qaeda-linked militants escaped was an inside job, Iraq's Interior Ministry said.

The ministry's statement issued late Friday also raised the death toll to 20, including 16 security force members and four inmates.

It said there was "clear collusion" between some guards and inmates at the Tasfirat prison in Tikrit, 80 miles north of Baghdad. Weapons were brought into the prison during family visits, and wardens left locks inside the facility open.

"The cells were not searched for a long period, which indicates more deliberate negligence that led to this incident," the statement said

Friday's security breach drew sharp criticism of Iraqi security forces, who have been unable to stabilize the country almost a year after the withdrawal of U.S. troops. It follows several smaller escapes and attempted jailbreaks that have deeply embarrassed Iraq's government, which is eager to demonstrate it can run its justice and detention system.

Of 303 inmates at the prison, 102 escaped in the jailbreak, including 47 Al Qaeda-linked inmates awaiting execution. Four were killed and 23 captured, the statement said.

After taking over a large part of the prison, the rioters used other inmates as human shields in order to make their way out, the statement said.

Immediately after the incident, authorities imposed a curfew in the city in an attempt to recapture the escapees.

A spokesman for Salahuddin province where Tikrit is located, Mohammed al-Assi, said Saturday that the curfew is still in force. "The security forces have intensified efforts to hunt down for those still on the run," he said.

The Interior Ministry statement meanwhile said that Salahuddin police chief, Maj. Gen. Abdul-Karim al-Khazraji, was sacked.

Authorities earlier reported 12 people dead in the break.