Pope Francis prayed for the victims of the Charlie Hebdo shooting, and for the Lord to "change the hearts" of the perpetrators, in a service on Thursday.

The pontiff said that the assault in Paris brought to mind "so much cruelty, so much terrorism," and expressed grief over the wanton violence that is seemingly sweeping the globe. 

"But how much cruelty is man capable?" Francis asked.

"We pray 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 hearts."

The Pope also tweeted support for Charlie Hebdo using the hashtag "#PrayersforParis."

On January 7, two masked gunmen forced their way inside the satirical newspaper's office and opened fire. Editor Stéphane "Charb" Charbonnier was killed, along with 11 others, including two police officers. An additional 11 staff members were injured. 

Reportedly, the Kouachi brothers repeatedly shouted "Allahu Akbar," Arabic for "God is great," during the shooting, and were trained by Al-Qaeda. The Islamic State (IS) praised the men for being "heroic jihadists."

Authorities named Saïd and Chérif Kouachi as suspects, and cornered the men in a building in Dammartin-en-Goele early Friday morning.

In a developing story, the brothers took hostages, and were engaging in gunfights with police but are reported to have been killed in the standoff. A third suspect turned himself in to authorities this week.  

Officials believe that the newspaper's controversial depictions of the Prophet Muhammad caused them to be targeted by the Muslim extremists.

The day of the attack, the company published a cartoon mocking IS leader Abu Bakr al-Baghdadi. The cartoonist, Philippe Honoré, was killed during Wednesday's attack.