Iran said Sunday a drone attack had targeted a defense ministry site in the central province of Isfahan without elaborating on the details.
A fireball lit up the night sky in video footage widely shared on social media and published by Iranian state media, with people outside seen running and emergency service vehicles speeding toward the site.
"An unsuccessful attack was carried out...on one of the workshop complexes of the ministry of defence," it said.
Authorities did not elaborate on the activities at the site, but IRNA said the strike had targeted "an ammunition manufacturing plant".
Parliament member Mohammad-Hassan Assafari told the Mehr news agency that "opponents and enemies" of Iran were aiming to "disrupt the defensive power" of the country with the attack.
The drone strike comes at a tense time in Iran, which has been rocked by protests over the death in custody of Kurdish-Iranian woman Mahsa Amini in September, and as the standoff with major powers over its nuclear programme remains unresolved.
Iran has also faced accusations by Western countries that it has been supplying armed drones to Russia for use in the war in Ukraine.