Aljazeera has learned that a bomber detonated his explosive-laden car at the main gate of the prison on Monday.
Sources from Abu Ghraib told Aljazeera that US soldiers were among casualties.
Monday’s attack was the second in less than 48 hours when fighters attacked the prison late on Saturday, injuring 44 US soldiers and 12 inmates.
At least 40 fighters fired rocket-propelled grenades and set off two car bombs on Saturday at the infamous prison as darkness fell.
Soldiers stationed at the detention facility responded and the fight lasted about 40 minutes, the US military said.
Abu Ghraib was at the centre of a prisoner-abuse scandal that broke out in 2004, when pictures depicting US soldiers piling naked inmates in a pyramid and humiliating them sexually became public.