The security forces have identified those who bombed a parade in the city of Mahabad, Iranian Minister of National Security Heydar Moslehi was quoted by Iranian news agency FARS as saying.
The explosion took place earlier this week during a parade in the city of Mahabad in the West Azerbaijan Province of Iran.
The blast killed 12 people and injured 58. Women and children were among the victims.
The province is densely populated with the Kurds and the Pejak group has been operating here.