At least 50 detainees have been killed during a militant attack on an Iraqi convoy south of the capital, Baghdad.
Officials said seven gunmen also died in the ensuing clashes on the morning of June 23.
They said the convoy was transporting the prisoners in the city of Hilla.
It was not immediately clear how the inmates were killed.
The development comes as Sunni insurgents are expanding their control of towns across northwestern Iraq, seeking to push toward Baghdad.
Officials said seven gunmen also died in the ensuing clashes on the morning of June 23.
They said the convoy was transporting the prisoners in the city of Hilla.
It was not immediately clear how the inmates were killed.
The development comes as Sunni insurgents are expanding their control of towns across northwestern Iraq, seeking to push toward Baghdad.