Iran: an escalation of terrorism?

The Iranian news agency, Tasnim has just reported a shooting and hostage situation at the Iranian parliament and that twelve people are reportedly dead.
However, there are conflicting reports across several state news agencies as to how many attackers were involved, whether one of the attackers blew themselves up with explosives, or whether security forces have now secured the site.
There has even been a claim that one of the attackers has taken a hostage and is still at large in the building.
Motivation for the attack (in whatever form it has taken) is being suggested by some quarters to be connected to another attack, where an armed assailant opened fire with a gun before blowing himself up at the late Imam Khomeini mausoleum in southern Tehran. Reports are suggesting several people have been injured in the attack.
Both locations are symbols of the Islamic Revolution. So were these attacks by a resistance force formed by people tired of what might be seen as a Islamist dictatorship, or a forward operating force created by a coalition of the Emirates and the Saudis?