Iraq's government vowed Wednesday to defeat "the terrorists" after a car bomb killed at least 51 people on a bustling street in a Shiite area of Baghdad and resolved to defend the security gains of the past year. No group claimed responsibility for the bombing, which occurred Tuesday evening on a busy commercial street in Hurriyah, scene of some of the most horrific sectarian cleansing in 2006. 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. The blast shattered the relative calm in the capital since a May 11 cease-fire ended seven weeks of fighting between US 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 US-protected Green Zone - a show of confidence that the worst of Baghdad's violence was over. In a statement, Prime Minister Nouri al-Maliki's Cabinet said the blast was aimed at raising the morale of extremist groups that have suffered setbacks in Baghdad, Basra and Mosul.