Around 15 labourers were engaged in work when the building collapsed due to water-logging at its basement, trapping all the workers under the debris, police said.
Three workers died in the incident while 12 others were injured, police said.
Rescue operations are still on, police said, adding the injured have been admitted to Badshah Khan Government Hospital.
The district town planner has been called and large number of police personnel have also been pressed into the rescue operation.
The contractor of the building is at large, police said.