TEHRAN, Jan. 19 (Xinhua) -- A 17-story commercial building, called Plasco, collapsed in Iranian capital Tehran on Thursday morning and dozens were trapped under the debris.

At 8:00 a.m. local time (0430 GMT), the fire started from the eighth and ninth floors of the building and soon spread to the upper floors.

The 54-year-old building was very fragile and ravaged by fire despite firefighters' efforts.

At least 30 people were injured, most of them firefighters.

Dozens of others, including some shop owners, were reportedly inside the building when it collapsed.