Rescuers received signals from life detectors in four locations under the rubbles in early hours of Saturday.
The operations were paused then for more careful and precise actions to reach the trapped ones. No survivor has been found yet.
Tehran Fire Department spokesman Jalal Maleki told state TV on Friday night that four bodies had so far been retrieved from the rubble.
Plasco Building caught fire in early Thursday and collapsed after four hours of burning, blockading 25 to 30 people under the detritus.
The discovery of two fire extinguishers belonging to the missing firefighters has stopped the use of mechanized debris removal equipment at the south side of the building. Rescue workers are now manually searching among the debris for any signs of bodies.
A firefighter’s body has just been dug out of the rubble in Plasco site after 48 hours.
Rescue team has dug a way to underground floors of Plasco building. So far, bodies of 3 firefighters have been recovered from under the huge rubble. It is estimated that the number of deaths to rise to 25 people. 16 firefighters were confirmed dead or missing, along with 9 civilians.