The dead included 15 women and four men, Maleki said, adding that firefighters had rescued 20 people. The spokesman said the explosion occurred as gas canisters caught fire in the clinic's basement. Deputy Tehran Governor Hamidreza Goudarzi earlier said that a leak from medical gas tanks in the building was the cause of the explosion. Tehran prosecutor Ali Alqasimehr said that those injured were transferred to Tajrish hospital for medical treatment.