Roses are placed in front of the French Embassy in the German capital on Jan. 7 as a tribute to the victims of a shooting at the Paris offices of the satirical weekly Charlie Hebdo. (Bernd Von Jutrczenka/European Pressphoto Agency)

After 12 people were killed by masked gunmen at the Paris offices of the satirical weekly Charlie Hebdo, many took to social media to post photos from the scene and to convey solidarity with the newspaper.

Read: Manhunt in Paris after massacre at newspaper office

Charlie Hebdo drew outrage across the Muslim world when it published crude drawings of the prophet Muhammad. In 2012, the man who drew the cartoons — who goes by the name Luz — said, “We treat the news like journalists. Some use cameras, some use computers. For us, it’s a paper and pencil... A pencil is not a weapon. It’s just a means of expression.” Read: What is Charlie Hebdo?

Je suis Charlie, which translates to "I am Charlie," started trending on social media as many showed support for the victims of the shooting. The U.S. Embassy in Paris also changed its Twitter profile image to this photo.

This was Charlie Hebdo's cover in 2012 that reemerged on social media in the wake of the shootings.

This video captured the attackers approaching the Charlie Hebdo offices, followed by gunfire.

The video below shows the scene outside the Charlie Hebdo offices.

In 2012, the newspaper printed cartoons that showed a naked Muhammad. In response, the French government shut down schools, embassies and other buildings in "preparation for any retaliation over the cartoons."

"Heard gunshots a while ago,"  wrote Instagram user andersvinsent. "There was a shooting 1 min from my apartment. Saw a ton of these guys doing their best to safe the situation. Horrible."

Photos: France on high alert