pope francis
Pope Francis leaves St. Peter's Basilica after celebrating the New Year Mass there in Vatican City Jan. 1, 2015. Reuters

Pope Francis held Mass on Thursday in honor of the victims of the Charlie Hebdo attack in Paris. Speaking at the chapel of the Santa Marta residence in the Vatican, Francis lamented “Of how much cruelty is man capable!"

He added, "We pray, in this Mass, for the victims of this cruelty -- so many of them -- and we pray also for the perpetrators of such cruelty, that the Lord might change their heart." The pontiff also tweeted “#PrayersForParis” on Thursday morning.

Throughout his papacy, Francis has remained dedicated to restoring ties with the Muslim community, a relationship that was strained under Pope Benedict XVI. On a trip to Turkey in November, Francis urged for greater interfaith dialogue.

“It is essential that all citizens -- Muslim, Jewish and Christian -- both in the provision and practice of the law, enjoy the same rights and respect the same duties,” Francis said in a speech to Turkish President Recep Tayyip Erdoğan. “They will then find it easier to see each other as brothers and sisters who are travelling the same path, seeking always to reject misunderstandings while promoting cooperation and concord.”

French President François Hollande called for a national day of mourning on Thursday. At noon, the country observed a moment of silence. Many stood silently in public squares and outside office buildings, and the Notre-Dame de Paris cathedral tolled its bells and offered Mass for the victims and their families.