The accident occurred on Thursday evening near Baradia Bazar area.
According to witnesses, the auto-rickshaw heading toward Matlab upazilla collided with the speeding microbus coming from the opposite direction, leaving driver Jashim dead on spot.
Of the five passengers of the auto-rickshaw three died at Chandpur Sadar Hospital.
Jannat Aktar Popy, 25, was admitted to the hospital in critical condition and other injured passengers could not be identified yet, said Mohammad Mohiuddin Mia, Officer-in-Charge (OC) of Matab Dakkhin police station.
The microbus driver managed to flee, said OC Md Mohiuddin.
After the accident agitated locals blocked Baburhat road for nearly an hour but police later brought the situation under control.