Suicide bombers who killed 95 people in attacks at Iraqi government ministries had been recently released from US custody, a senior interior ministry official has said.
The truck bombings in Baghdad on 19 August also wounded 600 people in what was the worst day of violence to hit the country for 18 months, dealing a major blow to the nation's security efforts in the wake of a major pullout of US troops.
The interior ministry official told AFP that the suicide bombers who attacked the ministries of foreign affairs and finance had been freed a few months ago from the Camp Bucca, the US jail near Basra.
A US army spokesperson said the army had no proof that a former detainee was involved in the bombings.
Since the start of this year 5,236 prisoners have been released from US custody and 1,179 detainees handed over to the government of Iraq, according to figures released on Sunday.
The interior ministry official told AFP that 14 suspects had been arrested in the wake of the attacks and the truck bombs were prepared in southern Baghdad.
"The vast majority of them were released in recent months from Camp Bucca," he said, noting all the suspects were from Nineveh and Salaheddin provinces.