The sound of a loud explosion heard in a town near Tehran has caused a stir among Iranian internet users, with reports of terrified people out in the streets.

The loud blast was first reported on Wednesday afternoon by the residents of the town of Shahr-e Qods (formerly known as Ghal‘eh Hasan Khan) west of Tehran.
It was labeled as an incoming missile explosion by twitter users which was rejected by a security official from the governor's office of the Tehran province.
The rumors prompted Iran’s Revolutionary Guards to issue a statement on the incident.
The public relations office of one of IRGC’s local bases announced that the explosion was the result of a “controlled rocket launch” that took place during a “regular training session” in the base.
The statement urged people to stay calm and no to trust the news from the social media.

There are no independent reports yet about the source of the loud explosion. The area is mainly residential and a missile or rocket test by the military seems strange. There are no known large military bases in the area suitable for a missile test.

Sounds of explosions lead to speculations of possible foreign attack, given several mysterious sabotage acts at Iran's well-defended nuclear and other sensitve targets since July 2020.