The incident took place in Geeta Colony at around 11.30 am. While the dead were labourers, the injured were those who were walking near the building.
Only one of the three deceased - Mohammed (35), hailing from Lakhimpur in Uttar Pradesh - has been identified.
The injured persons have been identified as Kapil Pandey (48), Mohit Pashwan (20), Ajay (23), Sarbulla (17) and Alibulla (18).
Police said a new room was being constructed on the second floor of the three storey building. The walls had become weak and it could not take the pressure of a new roof and collapsed.
A case of negligence has been registered.