Three car bombs shook Baghdad after dawn on Thursday, killing 15 people and wounding 50 in the second such attack within hours, police sources said. After dark on Wednesday another triple car bombing hit a mainly Shi'ite district of the city, killing 18, following meetings in Brussels between the new government, its U.S. sponsors and other foreign powers. Police said a suicide car bomber killed three policemen and wounded two when he drove at their patrol in the central commercial district of Karrada around 7 a.m. (0300 GMT). Two other cars exploded in the same area, each several minutes apart, one close to a Shi'ite mosque. Black smoke and flame darkened the morning sky. A bus lay charred and blood-stained outside Karrada's post office, shopfronts and roadside fruit stalls were devastated and trees lining the normally busy street were burned and uprooted. --SP 1342 Local Time 1042 GMT