Iran confirmed 20 fire fighters were killed in rescue operation at the Plasco building in southern Tehran which got fire and collapsed on Thursday morning.
Moreover 84 others have been wounded in the tragic incident.
Fire fighters have opened two tunnels to the building but have not managed to take out bodies yet.
The oldest 17-story structure in Iran has been the first modern and high building in the country established 53 years ago.
Out of 84 wounded people, 10 are still in hospital.
The rescue operation is underway slowly due to thick smog and fire.
Tehran Mayor, Mohammad-Baqer Qalibaf, confirmed the 20 fatality figure, emphasizing that this was not a final figure because a number of firefighters were trapped under the rubble as rescue operation to get them out continued.
Meanwhile, Tehran’s Governor General Hossein Hashemi said rescue workers were opening three separate routes in order to access those trapped below the debris from the collapsed building.
The 17-story structure crumbled after the fire engulfed the top floors of the building in downtown Tehran as scores of firefighters battled the blaze.
Later on Thursday, Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei issues a message expressing his condolence over collapse of the iconic building in downtown Tehran.
The Leader’s message read, "The painful incident of fire and collapse of a building in the center of the city is source of profound sorrow and concern for me. The valor and sacrifice of those firefighters, who were seriously harmed as they tried to rescue people and went through a difficult test while making committed sacrifice, fills one’s heart with [a sense of] admiration and praise as well as concern and sorrow.”
Ayatollah Khamenei emphasized that at the present time, all efforts should be oriented to saving those trapped below the rubble, and probing the causes of the incident must be the next step.
The Leader also urged all concerned officials to continue their diligent effort and fulfill their urgent duty without care for any possible gossip.