Police earlier said at least seven people were trapped in the collapse at an underground car park at a construction site, but it was unclear if some had since been rescued.
Police confirmed two people were killed and medics reported four or five people believed trapped at the site of the multi-floor car park, filled with twisted metal, dirt and rubble.
Surveillance video at the time of the collapse showed the area quickly enveloped by thick clouds of dirt and rubble.
Other medics with stretchers as well as ambulances waited nearby on standby. Search-and-rescue dogs were also at the scene.
While contact had been made with some of those trapped, leading to their rescue, the seven earlier reported missing by police had not been contacted.
The army said it sent search and rescue forces to "extract civilians".
"It is about four to five stories down under the surface," Avi Marcus, a medic with United Hatzalah rescue service who arrived on the scene shortly after the collapse, told AFP.
United Hatzalah said "firefighters and rescue teams are working to extricate" those believed missing.
"It appeared to me that the roof of a parking garage had collapsed in the building site," United Hatzalah quoted another of its medics as saying.
"While members of our ambu-cycle unit who arrived first on scene were treating the injured, reports came in of other people who were unaccounted for and likely still trapped inside."
Ramat Hahayal, an upmarket neighbourhood on the outskirts of Tel Aviv, is home to a number of high-tech offices in Israel's booming technology industry, based around the city of more than 400,000 people.
The cause of the collapse was not yet clear.
Israel has seen an unusually high number of construction accidents in comparison to the developed world.
Israeli newspaper Haaretz reported in May that 480 people were killed in construction accidents between 2000 and 2015.
Disclaimer: No Business Standard Journalist was involved in creation of this content
