DUBAI, United Arab Emirates (AP) — Iran fired air defense batteries early Friday morning after reports of explosions near a major airbase at the city of Isfahan, the state-run IRNA news agency reported.

It remained unclear if the country was under attack. However, tensions remain high after Iran’s unprecedented missile-and-drone attack on Israel. 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 defenses fired across several provinces. It did not elaborate on what caused the batteries to fire, though people across the area reported hearing the sounds.

In particular, IRNA said air defenses fired at a major airbase in Isfahan, which long has been home to Iran’s fleet of American-made F-14 Tomcats — purchased before the 1979 Islamic Revolution.

The semiofficial Fars and Tasnim news agencies also reported the sound of blasts, without giving a cause. State television acknowledged “loud noise” in the area.

Isfahan also is home to sites associated with Iran’s nuclear program, including its underground Natanz enrichment site, which has been repeatedly targeted by suspected Israeli attacks. However, state television described all sites in the area as “fully safe.”

Dubai-based carriers Emirates and FlyDubai began diverting around western Iran about 4:30 a.m. local time. They offered no explanation, though local warnings to aviators suggested the airspace may have been closed.

Iran later announced it grounded commercial flights in Tehran and across areas of its western and central regions. Loudspeakers informed customers of the incident at Imam Khomeini International Airport in Tehran, online videos purported to show.

Iranian state television began a scrolling, on-screen alert acknowledging a “loud noise” near Isfahan, without immediately elaborating.

Hossein Dalirian, a spokesman for Iran’s civilian space program, said on the X social media platform that several small “quadcopter” drones had been shot down. It wasn’t immediately clear where that happened or if it was part of the ongoing incident in Iran.

Meanwhile in Iraq, where a number of Iranian-backed militias are based, residents of Baghdad reported hearing sounds of explosions, but the source of the noise was not immediately clear.