Iran executed four men at dawn on Monday after they were convicted of collaborating with the country's arch-foe Israel on a plan to sabotage an Iranian defense site, according to the judiciary.

The four defendants, identified as Mohammad Faramarzi, Mohsen Mazloum, Wafa Azarbar, Pejman Fatehi, were arrested in July 2022 and accused of plotting to carry out out an operation against a Ministry of Defense centre in the central province of Isfahan, according to the judiciary's Mizan Online website.

"The death sentence of four members of a group affiliated with the Zionist spy organisation, who were arrested... for plotting a bombing operation in Isfahan, was carried out this morning," Mizan Online reported.

According to Iran, the men had been recruited by Mossad, Israel's intelligence service, "about a year and a half before the operation".

They were sent to African countries for "training courses in the military centres" where Mossad officers were present, the judiciary added.

The men were sentenced to death in September 2023.

In August 2023, Iran claimed to have foiled a "very complex" Mossad-initiated project to "sabotage" its ballistic missile industry. A few months earlier, in February, Teheran accused Israel of being responsible for a drone attack on a military site in Isfahan.

The two countries have been engaged in a shadow war for decades, with Iran regularly accusing Israel and its ally the United States of inciting unrest.