Iranian media reports say the country’s air defenses brought down three drones over the central city of Isfahan, hours after US broadcasters, citing senior US officials, reported Israeli missiles had hit an Iranian site.

The Iranian state-run media outlets have reported that at “around 1230 AM GMT” three drones were seen in the sky over Isfahan, air defense was activated and they “destroyed these drones in the sky.”

Iran’s Press TV says the sound of explosions have been heard near the central Iranian city of Isfahan and Tabriz in the country's northwest after air defense systems fired at "suspicious objects" early Friday.

ABC News reported earlier, citing a senior US official, that Israel had launched missiles at a site in Iran.  CBS News also reported that an Israeli attack had taken place.

Iranian media reports say airspace was reopened about four and a half hours after the incident and there were no reports of casualties.

Isfahan is considered a strategically important city and one that is host to several important sites, including military research and development facilities, as well as bases. The nearby city of Natanz is the location of one of Iran’s nuclear enrichment sites.

Nuclear facilities in Isfahan were reported to be “completely secure”, Iran’s Tasnim news agency reported, citing “reliable sources”.  Officials said important facilities in the Isfahan province, especially nuclear facilities, are completely safe and no accidents have been reported.

Al Jazeera reports that there were also reports of explosions in Iraq and Syria.

The United States and a number of European countries had been calling on Israel not to respond to Iran’s attack last week.

On Thursday, UN Secretary General Antonio Guterres painted a dark picture of the situation in the Middle East, warning that spiraling tensions over the war in Gaza and Iran’s attack on Israel could descend into a “full-scale regional conflict.”

“The Middle East is on a precipice. Recent days have seen a perilous escalation — in words and deeds,” Guterres told the Security Council.

“One miscalculation, one miscommunication, one mistake, could lead to the unthinkable — a full-scale regional conflict that would be devastating for all involved,” he said, calling on all parties to exercise “maximum restraint.”