TEHRAN, July 01 (MNA) – Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei offered commiserations over the death of a number of people in an explosion and at a medical clinic in northern Tehran, stressing the need for a probe into the causes of the incident.In a message on Wednesday, the Leader expressed condolences on the deadly explosion and ensuing fire to the families of the victims and called on the organizations in charge to launch an immediate probe to ascertain the causes of the incident accurately and expertly. He also emphasized the need for special care for the injured and the bereaved families of victims of the incident. An explosion at a medical center in the Iranian capital of Tehran on late on Tuesday left at least 19 people dead and more than a dozen others injured. The incident, reportedly caused after the explosion of three gas canisters, took place in one of the ground floors of Sina At'har Medical Center in northern Tehran late on Tuesday. Several emergency response units, including ambulances and firefighters, were seen deployed on site as smoke billowed from the building. MR/4963746