A number of folks had been injured on the Sina Athar clinic, and there are fears the loss of life toll will rise additional.
Iran’s state media quoted senior officers as saying the blast was brought on by a gasoline leak.
Tv photos confirmed plumes of smoke billowing within the sky. Firefighters extinguished the blaze a number of hours later.
Many of the victims of Tuesday’s blast had been girls, based on the authorities.
A number of the victims “were in upper floors, in operation rooms – who were either patients being operated on or those with them”, Tehran fireplace division spokesman Jalal Maleki was quoted as saying by state media.
“They unfortunately lost their lives due to the heat and thick smoke,” he mentioned, including that firefighters had rescued 20 folks.
The clinic, which carries out gentle surgical procedures and medical imaging, had 25 workers inside on the time of the explosion, Mr Maleki mentioned.
The incident comes a number of days after a giant explosion close to a navy facility rocked Tehran.
The reason for that incident was additionally mentioned by the authorities to have been a gasoline leak.