Tehran’s iconic Plasco building has collapsed as firefighters battled a blaze inside.
Iranian state television reports at least 20 firefighters have died and dozens of people were injured. Its feared a number of rescue workers may still be trapped under the rubble.
Between 150 and 200 people are reported to have been inside the tower at the time of the collapse.
Buildings in the surrounding area have been evacuated.
The blaze is believed to have started on the ninth floor.
Firefighters reportedly fought to control the blaze for hours before the 17-storey building started to crumble. It then toppled to the ground in a matter of seconds.
According to fire department spokesperson Jalal Maleki, ten stations responded to the blaze.
Built in the early 1960s, the Plasco tower stood close to the British and Turkish embassies, in the south of the city. Both have reportedly been evacuated.
Plasco housed 400 shops and businesses at the time of the collapse.
Its owner, Habib Elghanian, named it after his plastics manufacturing company. At the time of construction, it was the tallest building in the Iranian capital.
The Iranian Jewish businessman was later tried on charges including espionage and was executed in the months following the 1979 Islamic Revolution.
The movement brought the current ruling system to power, prompting many in the longstanding Jewish community to flee.