A car bomb exploded in northern Baghdad on Wednesday, killing 88 people and wounding at least 227 others, The Associated Press news agency reported.
Another 17 Iraqi civilians were killed by unidentified gunmen who surrounded a village north of Baghdad early Wednesday, according to AFP.
The car explosion took place at around 7 a.m. (0300 GMT) in a Shiite neighborhood.
The car was driven by a human bomber who struck a group of construction workers waiting to be hired for daily work in the Oruba Square in the Kazimiyah district, AP reported.
More than 50 small shops and several cars were damaged in the attack, witnesses said. Firemen were unable to reach the blast scene as cars were blocking nearby streets.
Iraq's Health Ministry said more than 88 people were killed and 227 wounded, making the explosion the deadliest attack in Iraq since Feb. 28, when a car bomb blast killed 125 people in Hillah.
A witness said the attacker drove into the square and called out that he wanted to hire daily laborers. When the people gathered around his car, he detonated his bomb.
"There were dozens and dozens of people around the car when it blew up," said Satah Jihad, a 40-year-old shopkeeper.
Jihad said that many of the day laborers come from poor Shiite areas in southern Iraq.
Gunmen kill 17 north of Baghdad
In Taji, about 15 kilometers north of Baghdad, a group of armed men arrested 17 people and shot them to death in a main square.
"Armed men dressed as soldiers and driving aboard military vehicles arrived in Taji and arrested several members of the Bani Tamin tribe before assembling them on a public square and shooting them," an Interior Ministry official said. The killings took place around 4:30 am in a mixed Sunni-Shiite neighborhood.
Police Lt. Waleed al-Hayali said the victims were handcuffed, blindfolded and shot to death.
The dead included one police officer and other people who worked as drivers and construction workers for the U.S. army, said al-Hayali.
Iraqi officials immediately condemned Wednesday's attacks. Husein al-Shahristani, deputy speaker of the National Assembly described it as "barbaric and gruesome."
"These cowardly attacks reveal the deep hatred of the terrorists against the Iraqi people and the equality and justice in this country," he said.
Constitution finalized
Meanwhile, Iraqi politicians agreed on last-minute amendments to the draft constitution in an attempt to appease Sunnis who refused to endorse the charter last month.
With the Oct. 15 constitutional referendum looming, Iraqi MPs announced that the charter had been finalized and would be sent to the United Nations for printing and distribution.
Hussein al-Shahristani, the deputy speaker of the National Assembly and a senior Shiite lawmaker, said the latest revisions included a clear bow to calls from the Arab League that the country be described as a founding member of the pan-Arab body and that it was "committed to its charters".
But that changes fall short of demands by Sunnis, who wanted the country's Arab identity clearly stated in the document while mentions of federalism be deleted.