Shahidul Islam's wife Shahnaj Begum was admitted to hospital in a critical condition.
Agitated local people blocked the road after the accident.
On information, officer in charge of Nageshwari police station, Nabiul Hasan and UNO Nur Ahmed Masum rushed to the spot and pacified the mob.
The accident occurred when a bus of Rizvi Paribahan hit the autorickshaw at 8:00pm, leaving two people dead on the spot.
The two others succumbed to their injuries on the way to Rangpur Medical College Hospital (RMCH).
Officer in charge of Nageswari police station Nabiul Hasan said the bus driver was detained.