Prime Minister Nuri al-Maliki on Saturday sacked the head of Iraq's prisons directorate and ordered senior police officers detained after hundreds of inmates escaped during assaults by Islamist militants.
An Al-Qaeda front group, the Islamic State of Iraq and the Levant, claimed the coordinated assaults on Baghdad's Abu Ghraib prison and Taji jail to the north, which began late on July 21 and sparked clashes that lasted for 10 hours.
More than 500 prisoners, among them senior Al-Qaeda leaders, escaped, while 20 security forces members and 21 prisoners were killed in the assaults.
A statement on Maliki's website said the initial findings of an investigation indicated a lack of oversight and that inmates were able to communicate with the outside world via mobile phones and other means.
The head of the prisons directorate has been dismissed, it said.
Various officers were also negligent in carrying out their duties, according to the investigation.
Maliki ordered that senior federal police officers responsible for protecting Abu Ghraib prison, police intelligence officers in the prison and police on duty during the escapes be detained, and their cases referred to the judiciary.
The prison assaults reflect the growing reach of militants in Iraq and a rapidly deteriorating security situation.
Violence in Iraq has killed more than 700 people in July, making it the deadliest month in a year marked by spiralling unrest that authorities have failed to stem.