Armed personnel opened fire on two passing vehicles they deemed suspicious outside the base in the city of Khomein, the semi-official ISNA reported, killing three people the report described as "martyrs".
A fourth person died from injuries sustained in the shooting later on Friday, according to the local governor.
The city’s public and revolutionary prosecutor said those involved in the shooting are under arrest, and that a judicial case has been opened for them. The wording of the state media report suggests the victims were civilians killed in error.
Tehran is reeling from intelligence lapses in the 12-day war which allowed its arch-foe to assassinate top military figures and wreak havoc on bases and nuclear sites.
Hundreds of civilians were killed in the shock campaign last month.
The shooting comes amid heightened domestic surveillance and arrests following the outbreak of war between Israel and Iran last month
Iranian authorities have detained at least 700 people on suspicion of collaborating with Israel, with hundreds reportedly arrested in Tehran as checkpoints have been deployed across major cities, and a new public hotline solicits tips for “suspicious behavior.”
The wide network of new checkpoints has expanded to cover nearly all city entry points, targeting private cars, buses and freight trucks.
On July 2, two young men were shot dead by the Islamic Republic's security forces outside Hamedan in western Iran.
Fars News Agency, which is affiliated with the Revolutionary Guards, reported that personnel opened fire on their vehicle near the Tareek-Darreh area after suspecting it of drone-related activity.
“Officers first fired warning shots, then issued a stop order before targeting the car directly,” Fars wrote.
The young men were on a recreational off-road trip — a common pastime in the area — and had no known political links, according to local reports. One other passenger was also wounded.
The Armed Forces Judicial Organization of Hamedan confirmed the deaths and said a formal probe was underway.
Swift reporting on the incidents appears to reflect official keenness to avoid stoking popular anger as economic malaise and political discontent persists.
The death of a young woman, Mahsa Amini, in Iranian morality police custody in 2022 stoked a protest movement in 2022 as shifting official explanations of her death failed to assuage popular anger. The demonstrations were quashed with deadly force.