Four people were killed while thirty others injured in car bomb explosion that targeted one of Iraqi capital's predominantly Shi'ite district of Karrada.According to an official report, the Karrada, major affluent district of the city Baghdad, was targeted by a booby-trapped car.A police officer was wounded in the blast while his vehicle was totally scorched down.Meantime, an Iraqi security source said the death toll and the injuries of the terrorist attack jumped to 46.