On Tuesday, police in Italy arrested the leader of an Islamic cultural center on financial and terror charges. Police tracked down his social media profile, finding support for the Islamic State (ISIS), along with videos of him teaching children as young as 4 years old to wield weapons against “unbelievers.”

“I invite you to fight the unbelievers, with your swords cut off their heads, with your explosive belts you blow their heads up in the air,” 58-year-old Abdel Rahman, an Egyptian with Italian citizenship, said to youngsters between the ages of 4 and 10, La Repubblica reported. “You must break the skulls of the unbelievers and drink their blood to get the victory.”

Rahman told the children that the only way to get to Paradise was by death in battle, investigators reported.

A joint police operation with financial fraud investigators, known as “bad teacher,” resulted in the capture of Rahman, who ran the Al Dawa Islamic Center, which also operated as a mosque. Investigators found a “discrepancy between the economic resources and the income declared.”

In addition to financial fraud and jihad indoctrination, investigators found evidence on social media that Rahman supported ISIS. They reconstructed his social media history, discovering that Rahman has supported ISIS since 2015.

Investigators also found “a lot of propaganda material, coming from the official ISIS networks, among which there was a video of [ISIS leader Abu Bakr] al-Baghdadi teaching children.”

Anti-terrorism police arrested the man, seized his bank accounts, and shut down the Al Dawa center after a thorough search. Rahman has been accused of terrorism and conspiracy to commit terrorism, The Local reported.

As for the children, who “were educated in the fight against the unbelievers,” police said the minors will be reported to the prosecutor’s office. Authorities intend “to check their psychological conditions and start a path toward achieving mental balance.”

In recent years, Italy has taken a hardline approach to alleged apologists for terrorism. In early 2015, the cabinet approved multiple anti-terror measures, including jail terms of up to six years for “foreign fighters” as well as those who would recruit would-be jihadis, passport confiscation from suspected militants, and giving broad powers to Italy’s intelligence services.

Under the new measures, Italy has deported more than 100 people for religious extremism.

Since May 2017, there have been four arrests and two deportations connected to the Al Dawa center. In July, police arrested a man from Chechnya who frequented the center and was believed to belong to a terrorist group in the Caucasus. Having fought in Chechnya and Syria, he was allegedly attempting to recruit more terrorist militants.

In a separate incident, a Tunisian and an Algerian were arrested and two Albanian brothers deported on charges of aiding or promoting terrorist groups.

Late last year, Interpol warned of 50 suspected ISIS terrorists who had entered Italy and might have spread throughout Europe.

Leaders have warned about the “Islamicization” of Italy, comparing the wave of refugees from the Middle East to an “invasion.” While such rhetoric is overblown, ISIS fighters infiltrated refugee networks, and cases like that of Abdel Rahman show that at least some immigrants are even attempting to radicalize children.

Indeed, on Wednesday, police arrested Moroccan-Italian Elmahdi Halili, who has also been charged with sharing ISIS propaganda online.