At around 2:16 am, a call was received regarding the collapse of a two-storey, old construction building in Kabir Nagar, Welcome area, North East DCP Joy said.

Two workers Arshad (30) and Tauhid (20) were declared dead at GTB Hospital while another worker Rehan (22) is critical and is under treatment, he said.

Legal action will be taken in the matter, Tirkey said, adding that further investigation is in progress.

Visuals from the spot showed rescuers carrying out a relief operation and standing on the heap of debris.

The first floor of the building was vacant at the time of the incident, while the ground floor was being used for jeans cutting, news agency ANI quoted an official as saying.

The owner of the building has been identified as Shahid, the report said, adding that efforts are currently underway to locate him.

"I was at home...Suddenly, I came to know that a building had collapsed and people were buried under the debris...Three people were buried, one of them was brought out; he had sustained a head injury. He told us that two more people were buried. They were brought out and taken to hospital but they died," a local told news agency ANI.