As if to prove that pens are mightier than swords, cartoonists around the world reacted to the cold-bloodied assassination of their colleagues at French satirical magazine Charlie Hebdo as only they can: with powerful drawings worth thousands of words.

Defiant, angry, poignant, irreverent and sobering, their drawings united cartoonists in grief, tried to make sense of the nonsensical, and sent a shared message: We must not, will not and should not be silenced. Some drawings touched such a nerve they made one want to both laugh and cry.

"Can't sleep tonight, thoughts with my French cartooning colleagues, their families and loved ones," David Pope, cartoonist for The Canberra Times in Australia, wrote on his Twitter feed.

His drawing showed the lifeless body of a cartoonist and a hooded gunman holding a still-smoking rifle and saying: "He drew first."

In India, cartoonist Manjul drew a plane exploding in a fireball into the Eiffel Tower, its pointy top redrawn as the nib of an ink pen.

One of the most powerful drawings had no drawing. Christian Adams' cartoon for The Daily Telegraph in London showed a completely blank space with the heading: "Extremist approved cartoon."

Another Telegraph cartoon showed one gunman saying to another: "Be careful, they might have pens."

The 12 people killed in the terrorist attack in Paris on Wednesday included some of France's leading cartoonists. Reveling in provocation and taking pride in their freedom to poke fun at anyone — be they popes, presidents, public figures or the Prophet Muhammad — they also faced frequent outrage and threats because of their work.