"These cases were immediately filed under the supervision of the esteemed investigators and are being investigated," Judiciary spokesman Asghar Jahangir told reporters in Tehran, adding that further information would be shared as it became available.

Iran's intelligence agency said in late July that it had identified and arrested "20 spies, Mossad operational and support agents, and elements connected to the regime's (Israel's) intelligence officers in Tehran" as well as several other provinces.

In mid-June, Israel launched an unprecedented bombing campaign against Iran, triggering a war during which Iran responded with missile and drone strikes.

The Israeli offensive killed senior military commanders, nuclear scientists and hundreds of others, striking both military and nuclear sites, as well as residential areas.

Iran has since vowed swift trials for those arrested on suspicion of collaborating with Israel.

"The judicial system will not show any mercy in dealing with spies and Zionist agents and will teach a lesson to all spies... with firm rulings," Jahangir said.

On Wednesday, Iranian authorities executed by hanging Roozbeh Vadi, a man convicted of spying for Israel by passing on information about Iranian nuclear sites and scientists.

Fars news agency said Vadi worked at the Nuclear Science and Technology Research Institute, a subsidiary of the Atomic Energy Organization of Iran (AEOI).

Iranian media also shared a screenshot showing an academic paper co-written by Vadi, alongside two nuclear scientists killed during the war, Ahmad Zolfaghar and Abdolhamid Minouchehr.