Iran has fired air defence batteries as explosions could be heard near a major air base near Isfahan, raising fears of a possible Israeli strike following Tehran’s unprecedented drone-and-missile assault on the country.

Iran’s Fars news agency said an explosion was heard at an airport in the central city of Isfahan but the cause was not immediately known.

Iran suspended flights early on Friday over the cities of Isfahan, Shiraz and Tehran, state media reported.

One Iranian government official suggested drones may have targeted sites.

State news agency IRNA said air 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.

Several Iranian nuclear sites are located in Isfahan province, including Natanz, centrepiece of Iran’s uranium enrichment program.

Tehran’s Imam Khomeini International Airport was closed to all flights until 7am GMT, according to a notice to airmen posted on a US Federal Aviation Administration database.

Some flights that were over Iran early on Friday made sudden sharp turns away from the airspace, according to flight paths shown on tracking website Flightradar24.

Israel had said it would retaliate against Iran’s weekend attack, which involved hundreds of drones and missiles in retaliation for a suspected Israeli strike on its embassy compound in Syria.

Most of the Iranian drones and missiles were downed before reaching Israeli territory.

Analysts and observers have been raising concerns about the risks of the Israel-Gaza war spreading into the rest of the region.

Iran told the UN Security Council on Thursday that Israel “must be compelled to stop any further military adventurism against our interests” as the UN secretary-general warned the Middle East was in a “moment of maximum peril”.

Oil prices jumped on the reports of the Israeli strike. Brent crude futures rose two per cent to $88.86 a barrel, the US dollar gained broadly, gold rose one per cent and S&P 500 futures dropped one per cent.

Israel’s assault on Gaza began after Palestinian Islamist group Hamas attacked Israel on October 7, killing 1,200, according to Israeli tallies. Israel’s military offensive has killed over 33,000 Palestinians in Gaza, according to the local health ministry.

Iran-backed groups have declared support for Palestinians, launching attacks from Lebanon, Yemen and Iraq.

– AAP with AP