TEHRAN, July 7 (Xinhua) -- Iran on Saturday executed eight people linked with the Islamic States (IS) attacks in the capital Tehran last year, official IRNA news agency reported.

"The death penalty for the eight terrorists was carried out according to legal and religious principles because of their involvement in attacks on the Mausoleum of Imam Khomeini and the Iranian parliament on June 7, 2017," Tehran Prosecutor's Office said in a statement.

Those executed collaborated directly with the key elements who killed and injured innocent civilians during the terrorist attacks, the statement read.

"They also provided arms and financial support to terrorists," it added.

In the 2017 IS twin attacks, 17 civilians were killed and six IS militants shot dead.