The incident took place near Tehran's Grand Bazaar, following which firefighters were immediately sent to the scene, Jalal Maleki, spokesman of the Tehran Fire Department, was quoted as saying.

He added that the explosion and the consequent fire had resulted in the partial collapse of an old two-story residential building and inflicted damage to an adjacent one, citing the cause of the incident as the explosion of a large amount of homemade fireworks.

According to Mohammad Esmaeil Tavakoli, head of Tehran's medical emergency organization, two of the wounded individuals were in critical condition.

Accidents caused by fireworks are more frequent in Iran in the days preceding the traditional Fire Festival, observed by Iranians on the eve of the last Wednesday before Nowruz, the Iranian New Year, which falls on March 20 this year.

(With UNI inputs)