Dozens of firefighters were feared trapped under rubble after Iran's oldest high-rise, the 15-story Plasco building in downtown Tehran, collapsed on live TV Thursday following a fire.

State television said 200 firefighters had been called to the scene and "tens" may have been inside when the building collapsed. Many had already been hurt before it came down, and initial figures said between 30 and 40 firefighters had been injured and seven hospitalized. Dramatic images showed flames pouring out of the top floors of the building, which dated from the early 1960's and included a shopping center and clothing workshops.

"The building's caretaker and some firefighters were inside when the building collapsed," said Ahmad, a shop owner in the building. "I've lost my entire stock. Thousands of families have been ruined," he added. The steel frame of the building could be seen bending down to the ground as about 100 fire engines and dozens of ambulances surrounded the area.

"A friend of mine has a shop there. I keep calling him but there's no answer. I think he's been trapped," said Mohsen, an onlooker. Police evacuated the area around the building, fearing secondary explosions caused by gas leaks, and worked to clear crowds that were blocking access for rescue services."There are a number of people inside but we don't know how many and the fire brigade organization is going to announce how many were there," Tehran police chief Hossein Sajedinia told AFP.

"Even one would be too many," he added. Fire brigade spokesman Jalal Malekias said the building was known to breach safety standards. "We had repeatedly warned the building managers about the lack of safety of the building," he said, adding that it lacked sufficient fire extinguishers.

"Even in the stairwells, a lot of clothing is stored and this is against safety standards. The managers didn't pay attention to the warnings," he told state television.

The Plasco building was the first high-rise and shopping center in Tehran and was the city's tallest building when it was finished in 1962, before being dwarfed by the construction boom of later years. It was built by Habibollah Elghanian, a prominent Iranian-Jewish businessman who was arrested for ties to Israel, sentenced to death, and executed after the 1979 Islamic revolution.

The fire is thought to have begun on the ninth floor and spread quickly to workshops above. Firefighters were initially able to bring it under control but it quickly flared up and the building fell four hours after the fire had started, at around 11:30 am.