The four are accused by police of publishing messages "against the person of the Holy Father," and saying, "Remember, there will not be another pope after this one; he will be the last."

One of the four was arrested in Kosovo, the police in Brescia said. Two were expelled from Italy and a fourth was placed on a terrorism "watch list" and his travel documents were confiscated.

The four were active on a Facebook group that indicated they had or aspired to have connections to Lavdrim Muhaxheri, a terrorist believed to be the leader of Muslims from the Balkan states fighting for the Islamic State terrorist group in Syria and Iraq, the Brescia police statement said. The four also posted photos of themselves "with weapons and in poses characteristic of combatants of the so-called Islamic State."