At least 19 people died, and others were wounded in an explosion at a clinic in Tehran, Iran’s capital.

The incident occurred at a clinic Sina Athar. Officials are afraid the death toll can skyrocket.

Senior officials said the explosion was due to gas leaks, according to Iran’s state media.

Hours later, firefighters extinguished the fire. Authorities have said the majority of the victims are women.

According to state media, Tehran fire department spokesman Jalal Maleki said that a few of the victims “were in upper floors, in operation rooms – who were either patients being operated on or those with them”.

“They, unfortunately, lost their lives due to the heat and thick smoke,”

He added the 20 people had been saved by firefighters.

He added that at the time of the explosion, 25 workers were inside the building.