The Pope's appeal was made Sunday after he prayed the Angelus with thousands of faithful gathered in St. Peter's Square.
"Serious news of attacks and violence continues to arrive daily from Iraq, shaking the conscience of all people who have the good of that country and the peace of the region at heart," he said. "Among this news, I learned today of the kidnapping of two good priests of the Syrian Catholic archdiocese of Mosul, who have been threatened with death.
"I appeal to the kidnappers to release the two religious immediately and, in underlining once again that violence does not resolve tensions, I raise to the Lord a heartfelt prayer for their liberation, for all those suffering from violence, and for peace."
The two priests, Father Mazen Ishoa, 35, and Father Pius Afas, 60, were kidnapped on their way to celebrate Mass on Saturday at Our Lady of Fatima Parish Church in the al-Faisaliya neighborhood, reported AsiaNews.
Negotiations are under way to free the priests.