The assault on the parliament appears to be over, after hours of intermittent gunfire there. A suicide bomber detonated a device at the mausoleum.
Iranian officials say they managed to foil a third attack.
The Islamic State group (IS) has claimed it carried out the attacks, which would be a first in Iran.
Five suspects have been arrested in Tehran, the city's police chief said.
Gunmen armed with Kalashnikovs entered the parliament on Wednesday morning. Heavy gunfire could be heard, and there were reports that a security guard has been killed.