The chief of air defense at Iran's nuclear facility in Natanz says they tested a missile to check preparedness in the region, after a loud explosion was heard.

Iranian air defenses fired a missile as part of an exercise on Saturday over the central town of Natanz, which houses nuclear installations, state TV reported, after local residents reported hearing a large blast.

The TV said air defense units fired the missile to test a rapid reaction force over Natanz.

Iranian news agencies earlier reported a large explosion in the sky above Natanz, but said there was no official explanation of the incident.

The semi-official Fars news agency quoted its reporter in nearby Badroud as saying a short blast was heard which was accompanied by an intense light in the sky.

Natanz was twice the target of highly destructive sabotage attacks in July 2020 and April 2021, widely attributed to Israel. Amid nuclear talks with Iran, Israel has repeatedly warned that it will not tolerate a nuclear Iran and will take action to stop Tehran from acquiring nuclear weapons.