Baghdad ? A car bomb ripped through a busy commercial street in a Shiite area of Baghdad on Tuesday, killing at least 51 people and wounding scores more in the deadliest blast in the capital in more than three months.

Many victims were trapped in their apartments by a raging fire that engulfed at least one building, according to police and Interior Ministry officials, who also said about 75 people were wounded. Stunned survivors stumbled through the rubble-strewn street, which was filled with the smoke from burning vehicles, witnesses said.

The attack shattered the relative calm in the capital since a May 11 cease-fire ended seven weeks of fighting between U.S. and Iraqi forces and Shiite militants in the Sadr City district. Ironically, it came the same day the Iraqi parliament announced plans to move outside the U.S.-protected Green Zone.