Air defence systems over the Iranian city of Isfahan were activated overnight, according to country's elite Revolutionary Guard on Tuesday.
Several explosions during the night had fuelled concerns of a possible Israeli attack.
The Iranian news agency Fars reported, citing a source in the Revolutionary Guards, that the air defence systems had reacted after sighting a "shining object."
According to the report, it was not a planned exercise and there was no enemy contact.
State radio described it as a defensive manoeuvre.
Just under a week ago, the Islamic Revolutionary Guard, Iran's elite military force, fired some 200 missiles at Israel. The attack came after a series of targeted killings by Israel of key players in Iran's network of non-state allies.
Israel had announced its intention to retaliate.
The city of Isfahan, with its Persian-Islamic architecture, is considered one of the country's most popular tourist destinations. The city is also home to important defence industry facilities and the country's nuclear programme.
