We know so little about them. The army of jihadists surprised just about everyone with their fast and violent sweep through Iraq. Now, vice news with stunning new images of the faces behind the... See More
We know so little about them. The army of jihadists surprised just about everyone with their fast and violent sweep through Iraq. Now, vice news with stunning new images of the faces behind the terror. The islamic militant group in Isis is so extreme that traditional Al Qaeda has disavowed it. Now, from vice news, video from inside the militant stronghold. Surreal scenes from a Syria city. Families enjoying the coolness of the euphrates. But even here, there's always something more sinister, even with the children. And what happens in Syria affects Iraq and vice versa. The treasures from the March on Baghdad are proudly paraded through the city along with new recruits from around the world. Here, the group is known simply as I.S. Or islamic state. At a night-time gathering recruiting continues. Beautiful virgins are calling. Enroll me as a martyr, this man sings. A call and a response to incite the crowd. Joining us now Kevin from vice news. Incredible images there. What do the people tell you about how this group has grown so rapidly and advanced so far? Well, less than a year ago, when vice news started covering Syria, Isis was a small factions fighting. 245i were just in the mix in the civil war in Syria. They have professionalized. They're an army now. You can see the way they swept across into Iraq. Establishing the caliphate. This is a force to be reckoned with. They've now got weapons they have looted from Iraq. American weapons. Tanks. They were -- he was there for three weeks and he saw how they're establishing a state. How do they hold territory? Do they encircle it, do they scare everybody? What's going on in these towns where they're holding people in Iraq like mosul? We filmed religious police walking around and enforcing the law. Minor infractions. The demand is to take it down. Women are told to put hijabs on to cover. The religious police are armed and everybody knows that you'll be going to prison and a judge could give you an amazing punishment. But you've got the air strikes going on right now around erbil. Will this scare them, stop them? I think that's to one side. They got 40% territory now. They are expanding now. They're expansionists. I think they'll welcome the attention the air strikes have brought them, the world attention. I think they have no fear. They're on a mission from god. They're very fundamentalists in their approach and I think we're just going to see more of this. We're not going to see less. Very frightening stuff. Thank you very much for those reports.
This transcript has been automatically generated and may not be 100% accurate.