A bomb in a car parked at a market in southwestern Baghdad has killed 22 people and wounded at least 30.
An Interior Ministry official said the wounded were nearly all civilians.
Witnesses said people in the market spotted a man park the car and make off despite efforts to apprehend him.
A police source said the car was parked along a street about 30 yards from a police checkpoint in a Shia part of the mostly Sunni neighbourhood of Dora. The blast left several cars burning and some nearby stores ablaze.
Another police officer said the bomb was detonated by remote control and an Iraqi suspected of triggering the device had been arrested.
Dora is among the most dangerous neighbourhoods in Baghdad, where car bombings and roadside bombs have been a daily occurrence since a Sunni-dominated insurgency began in the summer of 2003.
Twelve people were killed when a suicide bomber blew himself up on a bus in a Shia area of northern Baghdad yesterday. That bombing and other less bloody attacks have ended a relative lull in violence as political parties wrangle over the formation of a new government.