Cartoonists all around the world are tweeting their response to the terrorist attack at the French newspaper Charlie Hebdo, over 12 of France’s leading cartoonists including Cabu, Charb, Tignous and Wolinski – were killed in Wednesday’s deadly attack on the Charlie Hebdo satirical magazine in Paris.

The main target appeared to be Charb (real name Stéphane Charbonnier,) Libération newspaper reported.

“It was Charb they were targeting,” Libération quoted a police source as saying. “The two attackers looked for him in the room, shouting, ‘Where is Charb?’ Where is Charb?’

“They killed him then sprayed everyone else,” the source said, adding that perhaps other top cartoonists killed were also on the pre-prepared hit list

Can't sleep tonight, thoughts with my French cartooning colleagues, their families and loved ones #CharlieHebdo pic.twitter.com/LqIMRCHPgK — David Pope (@davpope) January 7, 2015

Still mortified about our fallen cartoonist colleagues, but free speech will always win. #CharlieHebdo #JeSuisCharlie pic.twitter.com/GHejOEXHwG — Rob Tornoe (@RobTornoe) January 7, 2015

My drawing in support of Charlie Hebdo https://t.co/lVQafVVAzh via @washingtonpost — Ann Telnaes (@AnnTelnaes) January 7, 2015