A series of bombs struck close to a dozen Iraqi cities as people went to work Tuesday morning.
The worst bombings, which came despite heavier than normal security ahead of next week's planned Arab summit in Baghdad, took place in the oil-rich northern city of Kirkuk and the southern Shi'ite holy city of Karbala.
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The greatest number of casualties occured in Karbala because a second bomb exploded after police and rescue workers arrived. That second explosion caught rescue workers by surprise, said a young man who works in Karbala.
Ambulances that arrived to help the wounded after the first blast, he said, and that is exactly when the second explosion took place. He indentified some of the victims as Iranian pilgrims.
Iraqi police and security forces were also targets of several blasts. A police official in Kirkuk told Iraqi state TV that suicide bombers blew themselves up in front of a police post.
The bombers were in a vehicle that tried to bust through security at the entrance of a garage used by police, the official said.
Khattar Abou Diab, who teaches political science at the University of Paris, said the attacks are probably a barometer of a growing divide between Iraq's Sunni and Shi'ite factions.
The wave of attacks reflect anger at Shi'ite Prime Minister Nouri al-Maliki who formed a unity government with other Shi'ite leaders and excluded top Sunni politicians from the decision-making, Abou Diab said.
He added the attacks may also be timed to discredit the government in the lead up to next week's Arab League summit in Baghdad.
Iraqi Foreign Minister Hoshyar Zebari told Al Arabiya television that “all Arab states plan to participate" in the summit. U.N. Secretary-General Ban Ki-moon plans to attend. The last meeting of Arab leaders in Baghdad took place in 1990.