The deceased, identified as Kamaljit Kaur, was the pillion rider on a scooter with her husband when the bus hit their vehicle from rear, police said.
Police said that Kaur's husband and their minor daughter who were also riding the scooter had a narrow escape in the mishap.
After the incident, a mob of the area set the bus ablaze. However, driver of the bus and conductor fled after the accident.
A relative of deceased told that Kamaljit Kaur was pregnant.