Baghdad's governor on Monday blamed negligence or even collusion by the security forces for devastating twin suicide bombings that killed around 100 people in the heart of the capital.
Governor Salah Abdul Razzaq said authorities had video footage showing the vehicles which exploded on Sunday, Iraq's deadliest day in more than two years.
The near-simultaneous bombings targeting the justice ministry and the Baghdad provincial government headquarters wounded more than 500 and left body parts and charred corpses scattered around the streets of the capital.
"It's a human failure... It can only be negligence or collusion," Razzaq told AFP, noting that footage showed a white Renault truck carrying two tonnes of explosives driving up to the justice ministry building.
The logo of the Department of Water in Fallujah, a former insurgent bastion west of Baghdad, was painted on the side of the truck, he said. "How did it get from Fallujah to here?"
Trucks are barred from entering Baghdad, especially the central Salhiyeh neighbourhood that was targeted, during daylight hours.
Razzaq said that the vehicle that was blown up in front of the provincial government building was a Kia minibus.
Prime Minister Nuri al-Maliki said that such attacks would not affect Iraqi support for democracy. On Sunday he had vowed that parliamentary elections scheduled for January would go ahead.
"The challenge ahead of us is great, but our confidence is also great," Maliki told researchers at an agricultural conference at Baghdad University. "Iraqis will not surrender or give up on their country.
Defence ministry spokesman Major General Mohammed al-Askari told AFP that security forces raided two houses in Baghdad, where they found bomb-making materials, and made arrests, but did not specify how many. Related article: Iraq's bloodshed
"It looks like the same materials used on Bloody Wednesday," he said, referring to August 19 bombings at government ministries in Baghdad that killed around 100 people.
Askari said the evidence found confirmed the bombers were linked to Al-Qaeda and supporters of the Baath Party of now-executed dictator Saddam Hussein.
The UN Security Council condemned the bombings, saying the attacks "underlined the need to bring perpetrators, organisers, financiers and sponsors of this reprehensible act of terrorism to justice and urged all states... to cooperate actively with Iraqi authorities in this regard."
Several roads in central Baghdad remained closed on Monday, with a heavy security presence on the streets, forcing many commuters to walk part of the way to work.
Dozens of Iraqi army humvees lined the roads while new checkpoints were established. Traffic was gridlocked outside a perimeter established around the bomb sites, with few cars allowed in.
Late on Monday evening, gunshots were heard in the vicinity of the justice ministry bomb site. A security official told AFP that looters had attempted to ransack the building and police had fired into the air to ward them off.
The bombs killed 99 people, a senior health ministry official told AFP on Monday, a figure confirmed by Dabbagh, Razzaq and Major General Qassim Atta, spokesman for the Iraqi army's Baghdad operations.
An interior ministry official, however, put the death toll at 155.
Among the dead were at least six children who had been playing in a nursery near the justice ministry, while 10 others were wounded.
The nursery itself was destroyed by the bomb, with blood covering the ground. At the entrance to the building were several boxes filled with children's shoes.
"We took all the injured children to the hospital -- I don't know if they are still alive," said army Colonel Khalil Ibrahim, chief of security at the justice ministry.
Al-Karama hospital in central Baghdad said the force of the blasts was so strong that it could not identify whether some corpses were male or female.
In the capital, rescue efforts were continuing on Monday. General Waleed Hamid said 600 personnel were sorting through the debris at the scene of the justice ministry bombing alone.
"It's possible that we will find more corpses," said Hamid, Baghdad's civil defence chief.
In a separate attack on Monday, three people were killed and five wounded in the Shiite holy city of Karbala, south of Baghdad, when a sticky bomb attached to a minibus exploded, officials said.
Plans for January's general election took a step forward when Iraqi leaders agreed a compromise on a key election law, amid growing concerns that polls scheduled for January might have to be delayed.
Maliki and other leaders drafted a new text that they will present to party leaders and senior lawmakers on Tuesday, deputy parliamentary sopeaker Khalid al-Attiya told AFP.