Pope celebrates Mass for Charlie Hebdo victims, prays for change of heart for "cruel" gunmen

Pope Francis has celebrated a Mass in memory of the victims of the Charlie Hebdo massacre, decrying the "human cruelty" that people are capable of.

Francis asked for prayers for the victims at the start of Mass and said "we also ask for those who are cruel so that the Lord may change their heart."

Francis also sent a one-line tweet from his @Pontifex handle: #PrayersforParis.

The Vatican has sought to mend relations with Islam that were initially strained under Pope Benedict XVI. Francis has a long history of promoting interfaith dialogue.

During Thursday's Mass, Francis said: "The attack yesterday in Paris makes us think about so much cruelty — human cruelty. ... Let us pray, in this Mass, for the victims of this cruelty."