Two senior security officials say a manhunt for the prisoners resulted in the killing of one and the arrest of 13 others. Eight are still at large.
The officials say the detainees killed the guard and escaped early today by a backdoor at the detention center in Baghdad's al-Adela prison.
Another guard says several guards were subsequently detained and are being questioned as possible accomplices. All officials spoke on condition of anonymity because they are not authorised to talk to media.