Transcript for Twin deadly attacks strike Iran's capital

We begin with the breaking news, twin terror attacks in the capital of Iran killing at least two security guards and injuring dozens, the scene still active and ISIS released video of the assault just moments ago and Martha Raddatz has extensive experience reporting inside Iran and tracking all the latest. Good morning. Reporter: State TV recording there are still two active gunmen inside the parliament building. Son-in-law of the male attackers dressed as women. These multiple attackers were clearly coordinated. Sophisticated and if it is ISIS, for Iran the attacks are unprecedented. Breaking now, ISIS releasing new video from inside the parliament building as the attack unfolds. This video showing a gunman walking into an office space before opening fire. It's one of two attacks in the heart of Tehran, assailants storming the parliament and gunshots ringing out in the street. Chaos outside as people flee. At least one of the attackers blowing himself up inside. Lawmakers in session when the siege began. Among those trying to escape, children. This picture showing police inside the parliament building helping a child to safety. While another attack began minutes away at the shrine of ayatollah khomeini detonating a bomb at the historic site. Overnight, ISIS claiming responsibility for the attacks. Again, the situation is very fluid. Those two gunmen still active inside the parliament building and, George, there are reports that one of the gunmen was actually outside and then able to return to the building, George. Well coordinated attack. A lot of Americans probably don't realize ISIS is an enemy of the Iranian regime but this is their first major attack inside the capital. Reporter: It truly is. This just does not happen inside Tehran. It was basically a suicide mission. I'm sure it will probably end with these gunmen but this is a huge wake-up call this morning, George, for Iran. Okay, Martha Raddatz, thanks very much.

This transcript has been automatically generated and may not be 100% accurate.