It was in October that an assailant opened fire on the Shah Cheragh mausoleum during evening prayers. 13 people were killed and 40 were injured. The perpetrator died in hospital a few days after the attack.
The two men who have now been executed were convicted of aiding and abetting the attack, and of having been members of IS. The terrorist group claimed responsibility after the deed.
According to Iranian media, the two men have confessed.