Iran executed three men on June 25 for alleged collaboration with Israel's Mossad intelligence service as authorities arrested hundreds of suspected spies during the recent 12-day conflict.

The executions took place in Urmia, West Azerbaijan province, with the men found guilty of espionage, weapons smuggling and equipment used to kill an unnamed Iranian official, judicial news agency Mizan reported on June 25.

Iranian security services detained approximately 700 people on espionage charges during the armed conflict between Israel and Iran, according to Nour News agency, as cited by CNN on June 25.

The detained individuals are accused of assembling explosive devices, filming strategic military sites, transmitting intelligence to Israeli structures and operating drones used in strikes on Iranian territory, sources told Nour News.

Security officials in Tehran confiscated around 10,000 drones allegedly intended for use in Israeli interests, according to investigators.

Kurdish human rights organisation Hengaw claims more than 530 people have been arrested across the country since the conflict began under the pretext of ensuring national security.

Total death figures from the 12-day war between Tehran and Tel Aviv total more than 600 deaths, according to the Iranian health ministry, the majority of which were targeted by locally launched drones. 

Iran's Ministry of Intelligence and National Security issued guidance asking citizens to report suspicious activities and released instructions for identifying Israeli spies and collaborators.

The guidance advises caution around strangers wearing masks or glasses, driving pickup trucks, carrying large bags or filming in military, industrial or residential areas.

Posters appeared on streets asking people to watch for suspicious individuals wearing "masks, hats and sunglasses even at night" and those who "frequently receive courier deliveries."

Citizens are also asked to report "unusual sounds from homes, such as screaming, sounds of metal equipment, continuous knocking" and "houses with drawn curtains even during the day."

The recent executions follow a previous death sentence carried out on June 16 against a man detained in December 2023 and accused of selling confidential data to Mossad.