At least 54 people lost their lives as a series of car bombs detonated in mainly Shi'ite Muslim districts of the Iraqi capital.
Dozens more have been wounded.
The deadliest single attack was here in Sadr City where a car packed with explosives blew up near a group of labourers.
Seven people were killed in that blast alone.
(SOUNDBITE)(Arabic) UNIDENTIFIED WITNESS SAYING:
"There was a white vehicle here and we were near the workers. Suddenly the vehicle went off and split into two parts. The first flew there while the other flew here."
In total 14 car bombs exploded across Baghdad.
It wasn't immediately clear who was behind the attacks.
But hardline Sunni Muslim militants who see Shi'ites as non-believers have been intensifying their insurgency this year.
The monitoring group Iraq Body Count says more than 6, 000 people have died in violence so far this year.
Iraq's delicate sectarian balance has been upset further by the civil war in Syria where mainly Sunni rebels are trying to overthrow a leader backed by Shi'ite Iran.
Both Sunnis and Shi'ites have gone to Syria from Iraq to fight on opposite sides of the conflict.