Pope Francis on Monday affirmed that Islam was not a violent religion.
The Pope said only a minority of its faithful were fundamentalists.
The Vatican City stated in a message that the Pope, who spoke on the plane while flying back from Poland to Rome, said it was not right to identify Islam with violence.
“I think it is neither true nor right to say that Islam is a terrorist religion,” he said.
The pope was in Poland from Wednesday to Sunday for the World Youth Day, a week-long event attended by over a million pilgrims.
A day before he left, an elderly Catholic priest was killed in Northern France during Mass, in an attack that the Islamic State claimed responsibility
The pontiff noted : “One thing is true, I think that in nearly all religions there is always a small group of fundamentalists, and it is a problem also for Christians.
“If I had to talk about Muslim violence, I would have to also talk about Catholic violence.
“Not all Muslims are violent, not all Catholics are violent.”
Pope Francis said Europeans should reflect on what drove disaffected youth to join the Islamic terror group.
According to him: “I ask myself how many young people, whom we Europeans have left empty of ideals, have no jobs and turn to drugs, alcohol or enrol themselves in fundamentalist groups.”