JERUSALEM — On the eve of a trip to the Middle East, Pope Francis is urging religious and political leaders to speak out against attacks on Christians by Islamic State extremists.

In an interview published Thursday, Francis was quoted as saying that the persecution of Christians today is "the worst" it has been since Christianity's earliest days. "In Iraq, for example, barbaric, criminal indescribable things are being committed," he was quoted as telling the Israeli daily Yediot Ahronot.

Francis told the newspaper that the persecution of Christians, Yazidis and other ethnic communities requires both political and religious leaders, especially Muslims, to "take a clear and brave stand."

Francis is set to travel to Turkey on Friday for a three-day visit.

Yediot said it would publish the full interview on Friday.