The accident occurred yesterday on Shyamnagar flyover when Rita (25) was going home with her brother Happy (20) on the motorcycle. The truck coming from behind hit the motorbike killing the girl on the spot, they said.
Happy has been admitted to a private hospital while Rita's body has been sent for post mortem, police said.
The truck driver fled from the spot after the incident.
Locals protested against the incident but were later pacified by the senior police officials.