Iran says it has executed eight people convicted over the twin 2017 Islamic State (IS) attacks on parliament and the shrine of the founder of the Islamic republic, Ayatollah Ruhollah Khomeini, in Tehran.

Iran’s Judiciary said the eight men had been working with those responsible for the deadly attacks and provided them with weapons and financial support, the Judiciary-affiliated Mizan news agency reported on July 7.

Mizan named those executed as Soleiman Mozafari, Esmail Sufi, Rahman Behrouz, Seyed Majed Mortezai, Sirous Azizi, Ayoub Esmaili, Khosro Ramezani, and Osman Behrouz.

It wasn’t clear when the executions took place.

The June 7, 2017, attacks on Iran's parliament and the shrine killed at least 17 people and wounded more than 40.

The attacks were the first act of terror inside Iran claimed by the extremist group.

Five gunmen died, either in suicide bombings or killed by Iranian security forces.

Over a dozen others remain on trial over the attacks.

Iran's Islamic Revolutionary Guards Corps (IRGC) later said it had responded to the attacks by launching several ground-to-ground missiles into eastern Syria, targeting “terrorists.”

Iran has been a key backer of Syrian President Bashar al-Assad during the country's civil war and the IRGC has played a crucial role on the ground.

With reporting by AP, IRNA, and mizanonline