TEHRAN 

At least 19 people were killed Tuesday when a gas leak at a health clinic in Iran's capital Tehran caused an explosion.  

Six others were injured, Peyman Saberian, head of Tehran’s emergency services, told the semi-official Fars News Agency. 

Tehran Deputy Governor Hamid Reza Goudarzi told state television that a gas leak caused the blast. 

The street where the explosion occurred was closed to traffic and strict security measures were taken at the scene. 

A number of videos were posted on social media showing the aftermath of the incident with thick smoke coming from the site of the blast.

*Writing by Havva Kara Aydin and Burak Dag