Baghdad: The suicide bombers who killed 95 people in devastating attacks at Iraqi government ministries on August 19 were recently released from US custody, a senior Interior Ministry official said on Sunday.
The truck bombings in Baghdad 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 country`s security efforts in the wake of a major pullout of US troops.
"The suicide bomber who blew himself up at the Ministry of Foreign Affairs was released three months ago from Camp Bucca," the official said on condition of anonymity, referring to the US jail near Basra.
"The suicide bomber who blew himself up outside the Ministry of Finance was also released a few months ago from the same jail."
Since the start of this year 4,000 Iraqi prisoners have been freed by the Americans and handed over to Iraqi officials, who then take the decision on whether they stay in prison.
About 11,000 prisoners were still in US custody, according to figures released in June.
"We have no proof that a former detainee was involved in the bombings," a US Army spokesman said on Sunday.
"The government of Iraq is still investigating the attacks, and it would be inappropriate for us to speculate as to who may have been involved while the investigation is ongoing."
The Interior Ministry official, however, said that 14 suspects had been arrested in the wake of the attacks and that the truck bombs were prepared in southern Baghdad.
"The vast majority of them were released in recent months from Camp Bucca," he said.
"Each of them had a precise role. One was responsible for buying the trucks. One was in charge of making sure they could enter Baghdad. One made sure that the explosives were packed on the trucks and others were the suicide bombers."
The disclosure contradicts an official version of events which last Sunday saw the government parade a former police chief who they said orchestrated the Finance Ministry bombing.
Wissam Ali Kadhem Ibrahim admitted to plotting that attack.
"I received a call a month ago from my boss in the (Baath) party Sattam Farhan in Syria to do an operation to destabilise the regime," Ibrahim said in video footage, alluding to executed dictator Saddam Hussein`s now outlawed political movement.
The 57-year-old suspect said the truck bomb was prepared in Khalis, 80 kilometres (50 miles) northeast of Baghdad, and that he had called a contact in the nearby town of Muqdadiyah to ensure its safe passage to the capital.
Ibrahim, who said he was a chief of police in Diyala until 1995 under Saddam`s rule, said he had worked as a lawyer until 2002 but then became a leading Baathist official in the restive province northeast of Baghdad.
Major-General Qassim Atta, spokesman for the Iraqi Army`s Baghdad operations, told reporters that Ibrahim was the main person responsible for the attack at the Ministry of Finance.
The second truck bombing occurred just minutes later at the Foreign Ministry.