Twin attacks on the Iranian parliament and Ayatollah Khomeini's mausoleum in the capital, Tehran, have caused a number of deaths and injuries.
The assault on the parliament building may be ongoing, with conflicting reports of a hostage situation. A suicide bomber died at the mausoleum.
Iranian officials say they have foiled a third attack.
The so-called Islamic State group (ISIS) has claimed it carried out the attacks, which would be a first in Iran.
ISIS later posted a video which showed what it claims is footage from inside the parliament building.