RENEE MONTAGNE, BYLINE: Najibullah Quraishi has covered militant groups in Afghanistan for over a decade. And he's now the rare journalist who has gotten access to ISIS-held territory. It was a dangerous journey. And he told me even he was surprised that this brutal brand of militants had appeared in his country.
NAJIBULLAH QURAISHI: To be honest, when I heard first about ISIS in Afghanistan, I didn't believe this because we invested so much. We paid so much life to bring peace and to fight against these insurgency and terrorist groups. But now we have ISIS in Afghanistan, which is horrible.
MONTAGNE: You - you say yourself in the film the area that they control was first controlled by Taliban. So what is the change, other than a new black flag where once there was a Taliban flag?
QURAISHI: Well, not only the Taliban was in power on that region. Most of the area we went belong to al-Qaida in the past. They simply changed their side and they become ISIS. It was in - some times in June 2014, they came to Afghanistan. And they - they just hanged up 12 Taliban commander.
MONTAGNE: They were - they were hanged as a - as a message.
QURAISHI: Yes. Yes. This was their first message for - for all the Taliban. And they - they were basically telling them to join them. Otherwise, somehow they'll be killed.
MONTAGNE: I'd like to play a scene from your documentary. In this village, there were a group of very young children, boys and girls, gathered into a classroom. Their teacher is an ISIS fighter. He's asking them to basically learn by rote.
(SOUNDBITE OF DOCUMENTARY, "ISIS IN AFGHANISTAN")
UNIDENTIFIED MAN: (Foreign language spoken) Jihad.
UNIDENTIFIED STUDENTS: Jihad.
UNIDENTIFIED MAN: Jihad (foreign language spoken) jihad (foreign language spoken).
UNIDENTIFIED STUDENT: Kalashnikov.
UNIDENTIFIED MAN: Kalashnikov.
MONTAGNE: Kalashnikov - I mean, pretty stunning. He - he's - also shows them not the - not just the gun but then a grenade, points to pulling the pin. Talk to us about all of that.
QURAISHI: Well, the - the things which really, really shocked me was to see those children at the school. So I thought maybe they get some proper lesson at their school, like some grammar, maybe some math or something like this or even to learn about proper Islam. Then they start, what is jihad. Teaching children three or four years old up to nine or 10 years old what is jihad. And then later on - later on on that day, they were - they were watching some - some beheadings, some torturing videos, which they were receiving from Syria and Iraq in front of the children.
MONTAGNE: And the children were seeing them?
QURAISHI: Yes. Yes. They were inviting the children to watch this. I ask him is that right to show these kind of things for - for the children? They said yes, yes, they should know from now. So these are - would be our - our next generation.
MONTAGNE: How much of a draw is the ability of ISIS to pay its fighters more than - than the Taliban and by a lot? In the film - in the documentary - they were talking about $700 a month, which is a huge sum in Afghanistan.
QURAISHI: So Afghan army, they get $300 per month. And most of the time it's delayed. After five months they get two months' salary. And they cannot support their family. And that's why thousands of Afghan troops left the army. But ISIS offer $700 and they pay monthly. And without any delay. And most of the Afghan people, especially the young generation, they are unemployed. So of course everyone going to join them. They are poor. They don't have anything to eat. And they want to support their families. And also the way they - they pitch their ideas -their opinions on these people - they are very clever. They say and God says this and Quran says this and because these people are uneducated, they can't read Quran. They don't know about Islam. So they think, yes. He is right. Let's do whatever he's saying. So that's why ISIS succeed in Afghanistan. And day by day they - they are recruiting people.
MONTAGNE: Thank you very much for joining us.
QURAISHI: Thanks a lot.
MONTAGNE: Najibullah Quraishi's "FRONTLINE" documentary is called "ISIS In Afghanistan." It airs tomorrow on PBS stations. Transcript provided by NPR, Copyright NPR.