TEHRAN, Jan. 22 (MNA) –  A loud blast heard in the city of Garmsar in Iran's northern Semnan province on Monday was caused by a fighter jet breaking the sound barrier, a source has said.

An informed source told the IRNA on Monday that at about 09:15 am local time (0545 GMT) a fighter jet flying at a level lower than permissible altitude broke the sound barrier and caused a loud blast. 

The governor of Garmsar also told the IRNA that there had been no explosions in the city's industrial park as reported by some media outlets earlier on Monday. 

Earlier on Monday, the sound of a massive explosion was heard in Garmsar city in the southeast of Tehran.

Media sources reported that the sound was heard in Garmsar industrial town.

MNA/IRN