Terrorist operation had started at 10:15 local time (5:45 GMT), according to IRNA.
In an apparently coordinated attempt, two terrorist groups attacked mausoleum of the late Imam Khomeini, southern Tehran, and the Iranian Parliament (Majlis) on Wednesday morning, killing 12 people and injuring 42 more.
One of the attackers, reportedly a woman, blew herself up outside the Imam Khomeini shrine.
The terrorist group of Daesh (ISIS) has claimed responsibility for the fatal attacks in Tehran.
One of the terrorist was gunned down by the security forces and the other one exploded herself at the mausoleum.
Terrorists entered the Parliament building while they had dressed as women, said a security official.
Parliament operation ended by security forces who killed three of the terrorists, one of them had detonated himself before.
Meanwhile, according to an official at the Intelligence Ministry, several terrorist cells have entered Tehran to carry out terrorist operations but members of one of the cells have been arrested.
EghtesadOnline: Terrorist operation in Iran’s Majlis(parliament) ended and four assailants were killed by the Islamic Revolution Guard Corps (IRGC) special forces.