Two persons were killed and several others injured when a speeding bus overturned on Kolkata's iconic Howrah bridge on Friday, a city traffic police officer said."A speeding minibus went out of driver's control and flipped over after hitting the road divider on the Howrah Bridge, killing two passengers and injuring several others," the officer said.The injured passengers were rushed to a city hospital.The accident during the busy office hours, caused massive traffic jam on the bridge for more than half an hour. The bus was later removed, using a crane. The driver ran away."A case of reckless driving has been registered. Police are looking for the driver," the officer added.