More than 150 people are feared dead following a series of bomb and suicide attacks in and around Baghdad.
A suicide bomber lured a crowd of Shia day laborers to his minivan before blowing it up, killing 114 and wounding more than 156 in Baghdad's old town.
The bomber drew the men to his vehicle with promises of work before detonating the bomb, which contained up to 500 pounds (220 kg) of explosives, an Interior Ministry source said. It was the second deadliest single attack since the US-led invasion of March 2003.
"There's no political party here, there are no police," Mohammed Jabbar railed at the blast site in the Shia Kadhimiya area.
"This targeted civilians, innocents. Why women and children?" he added, as bystanders shouted, "Why? Why?"
Another car bomber blew himself up in northern Baghdad, killing 11 people lined up to refill gas canisters, as bombings rocked the capital.
Gunmen also dragged 17 people from their homes and killed them in Taji, a northern suburb.
A police official said the attacks appeared coordinated.
An Islamist Web site often used by a Sunni Muslim militant group led by Abu Musab al-Zarqawi claimed it was waging a nationwide suicide bombing campaign to avenge a military offensive on a rebel town.
The statement did not mention a specific attack, but said the campaign was in reprisal for a US-Iraqi offensive in the northern town of Tal Afar.
"We would like to congratulate the Muslim nation and inform it the battle to avenge the Sunnis of Tal Afar has begun," it said.
Fears of civil war have grown ahead of an Oct. 15 referendum on a new constitution for Iraq.
Iraqi government officials have accused Sunni militants of attacking majority Shi'ites, who swept to power in January polls boycotted by most Sunnis, in a bid to spark a civil war.
Most of the victims of today's attacks were Shias.
"We gathered and suddenly a car blew up and turned the area into fire and dust and darkness," said Hadi, one of the workers who survived the attack, which happened shortly after sunrise.
Bodies lay in the street beside burned-out cars, witnesses said. Some used wooden carts to haul away the dead. Police said 114 people were killed and 156 wounded in the blast.
The death toll has only been exceeded since the start of the war by a suicide car bombing on February 28th this year, which killed 125 people in Hilla, south of Baghdad.
Earlier this month more than 1,000 people died in Kadhimiya in a stampede on a bridge, triggered by fears of a bomber in a crowd during a Shi'ite religious ceremony.
At the nearby Kadhimiya hospital, overflowing with victims, dozens of the wounded screamed in agony as they were treated on the floor, some lying in pools of their own blood. One man had severe burns to his arms and legs, and another victim, shivering uncontrollably, lay bleeding unattended.
Another blast echoed over central Baghdad about two hours after the first. Two more car bombs exploded soon afterwards.
Police said five people were killed and 24 wounded in one of the blasts, near a Shia cleric's offices. Three policemen and three civilians were killed in an attack on a police convoy.
A US patrol also came under attack. A Reuters cameraman saw a Humvee military vehicle burned out by a roadside bomb. There was no word on any US casualties. Minutes later another bomb nearby wounded two Iraqi policemen in a convoy.
The gunmen in Taji had rounded up their victims in the middle of the night. All were shot in the head, and all were Shia relatives from the same tribe, police said.