Iran has fired air defence batteries after reports of explosions near the city of Isfahan, the state-run IRNA news agency reported.
It remained unclear if the country was under attack.
One government official suggested sites may have been targeted by drones.
The Israeli military did not immediately respond to a request for comment.
IRNA said the defences fired across several provinces.
It did not elaborate on what caused the batteries to fire, though people across the area reported hearing the sounds.
The semiofficial Fars and Tasnim news agencies reported the sound of blasts, without giving a cause.
State television acknowledged “loud noise” in the area.
Commercial flights began diverting their routes over western Iran without explanation early today as one semiofficial news agency in the Islamic Republic reported “explosions” heard over the city of Isfahan.
State television acknowledged “loud noise”.
The incident comes as tensions remain high in the wider Middle East after Iran’s unprecedented missile-and-drone attack on Israel.
Dubai-based carriers Emirates and FlyDubai began diverting around western Iran about 4.30am local time.
They offered no explanation, though local warnings to aviators suggested the airspace may have been closed.
The semiofficial Fars news agency reported on explosions being heard over Isfahan near its international airport.
It offered no explanation.
However, Isfahan is home to a major airbase for the Iranian military, as well as sites associated with its nuclear program.
Iranian state television began a scrolling, on-screen alert acknowledging a “loud noise” near Isfahan, without immediately elaborating.
The Israeli military did not immediately respond to a request for comment.
