by Priyanka Boghani

Young boys and girls cluster around a small room in a village school in eastern Afghanistan. The teacher calls on a young boy.

“Stand up, Daud. What is this called?” he asks, handing the boy an AK-47.

“Kalashnikov,” the boy replies.

“Why do we use this?”

“To defend the faith,” Daud responds.

The school is run by fighters who pledged allegiance to ISIS — the terrorist group that declared an Islamic caliphate in Iraq and Syria. They live among the locals in the village of Shaigal, take local wives and collect taxes. They seem to control every aspect of life.

The teacher, Abdullah Gul, tells the students what “jihad” means: “We must implement God’s religion over all people,” Gul tells the children in the below video. “God says do jihad until intrigue, idolatry and infidelity are finished in the world.”

The footage — from the upcoming FRONTLINE documentary, ISIS in Afghanistan — is some of the first to show the degree to which ISIS has gained a foothold in the country, introducing a new level of brutality to the conflict, beyond what has been practiced by the Taliban. Fighting between ISIS, the Taliban, and government forces and allied militias has displaced a new wave of Afghan civilians, many of whom have made the treacherous journey across the Mediterranean Sea to seek refuge in Europe.

Those who remain in Afghanistan face an increasingly deadly conflict. The first six months of 2015 saw the highest death toll — 1,592 — since the United Nations began counting in 2009. The rising deadliness and complexity of the conflict led President Barack Obama to announce in October that the United States would keep 9,800 troops in Afghanistan through 2016.

ISIS in Afghanistan will air on PBS on Tues., Nov. 17 (check local listings here) and online on the FRONTLINE website.