At least 12 labourers were in the under-construction building and all of them were feared trapped, Chief Fire Officer (CFO) Arun Kumar Singh said.
Two bodies were pulled out of the rubble late last night and another removed this morning as 150 personnel as the National Disaster Response Force (NDRF) mounted a rescue operation along with the police and the fire department.
Five more bodies were brought out in the evening and later at night.
Rescuers deployed heavy machinery to shift concrete slabs and used drills in a bid to reach people buried under the debris. Sniffer dogs tried to detect any sign of life
A crowd of people hung around the mishap site, including some who believed their relatives were trapped under the debris.
Some flat owners who were planning to move into their new homes in the next few days also watched the rescue effort.
Local politicians and media teams thronged the area as NDRF personnel asked people to keep away.
Three of the victims have been identified as Ranjit, Shamshad and Priyanka. Three members of Priyanka's family were still trapped, Singh said after her body was pulled out.
The police have arrested four people, including the landowner. Altogether, 24 people have been named in the FIR. Charges include culpable homicide not amounting to murder.
Officer on Special Duty (OSD) in Greater Noida Development Authoriity, Vibha Chahal, has been removed from her post.
Uttar Pradesh Chief Minister Yogi Aditya Nath also ordered the suspension of two other officials, project manager V P Singh and assistant project manager Akhtar Abbas Zaidi, for dereliction of duty.
Adityanath asked the Meerut divisional commissioner to conduct an inquiry and determine the extent of illegal construction in the area.
Earlier in the day, Gautam Budh Nagar District Magistrate Brajesh Narayan Singh had also ordered an investigation into the mishap, to be completed within 15 days.
"They have tried to sell an unauthorised construction to the people. We will initiate proceedings under the National Security Act against them," Singh told PTI.
NDRF Director General Sanjay Kumar took stock of the rescue operations.
He said the rescuers were exercising caution while operating the machines so that those trapped under the debris were not harmed. This was leading to the delay, he said.
Kumar said the rescue operations were likely to be completed on Friday.
A state government statement said a magisterial probe will find out whether the buildings were under the jurisdiction of the Greater Noida Development Authority and if a no-objection certificate (NOC) was obtained before carrying out the construction.
It will also determine if the quality of the building material was up to the mark and the construction workers were registered in accordance with the labour laws.
In a press statement, the Greater Noida authority CEO Parth Sarthi Sen Sharma said Shahberi is a "notified village" under phase-1 of Greater Noida.
But the notification related to acquisition of land there was cancelled by a Supreme Court order in May 2011, he said.
Local residents claimed that some builders had purchased land directly from the farmers and developed an unauthorised colony.
According to the FIR lodged at Bisrakha police station, poor quality material was used in the construction of the building.
The FIR said district authorities had been warning builders and contractors in general against unauthorised construction.
Three of those arrested have been identified as landowner Ganga Shankar Dwivedi and brokers Dinesh Singh and Sanjeev Kumar, both residents of Shahberi.