According to reports, a dozen people have been killed in the attacks while another 42 have been injured and admitted to 3 hospitals to receive treatment.
The Daesh Takfiri terrorist group has claimed responsibility for the attacks.
At least four gunmen reportedly intruded into the premises of the Majlis, opening fire on the security guards there. The assailants were all killed by security forces following the attack.
The assault has forced a lockdown on the legislature.
Tehran MP Elias Hazrati has said that the assailants were armed with two Kalashnikovs and a handgun.
According to lawmaker Mehdi Kiaee, the situation is under control inside the parliament, while security forces are working to restore calm there.
asnim said in an update that the hostage rescue team of the Islamic Revolution Guards Corps (IRGC) has arrested two “terrorists” in the Imam Khomeini Mausoleum.
An Interior Ministry source said a bomber has blown himself up on the fourth floor of the parliament building, where he was holed up.
Separately, Fars said in a Twitter post that three gunmen attacked the Imam Khomeini Mausoleum in Tehran, opening fire on people inside and wounding a number of them.
The report said one of the assailants has been killed, another has blown himself up and a third one has been injured.
Informed sources say a bomber’s explosive vest has also been discovered and deactivated in the vicinity of the mausoleum.
Iran’s state television quoted an Intelligence Ministry source as saying that the twin attacks in Tehran were being treated as terrorist incidents.
IRNA cited an official with the Intelligence Ministry’s Counter-terrorism Department as saying that several terrorist teams had entered the capital earlier in the day.
One of the terrorist teams was busted before managing to stage any attacks, while two others attacked the parliament building and the mausoleum. At the shrine, one bomber was killed before setting off his explosives, but another managed to blow himself up.
Parliament Speaker Ali Larijani condemned the attack as “cowardly” and said the attacks meant to undermine Tehran’s anti-terror fight.
Meanwhile, Deputy Interior Minister for Security Affairs Hossein Zolfaqari said the country’s Supreme National Security Council will hold a meeting later in the day to investigate the different aspects of the attacks.
The Takfiri Daesh terrorist group has claimed responsibility for the Tehran attacks through its propaganda outlet Amaq.
[This item is being updated.]