Canadian Prime Minister Justin Trudeau defended free speech on Friday, but added that it was "not without limits" and should not "arbitrarily and needlessly hurt" certain communities.

"We will always defend freedom of expression," Trudeau said in response to a question about the right to show a caricature of the Prophet Muhammad, as Charlie Hebdo magazine did.

"But freedom of expression is not without limits," he added. "We owe it to ourselves to act with respect for others and to seek not to arbitrarily or unnecessarily injure those with whom we are sharing a society and a planet."

"In a pluralist, diverse and respectful society like ours, we owe it to ourselves to be aware of the impact of our words, of our actions on others, particularly these communities and populations who still experience a great deal of discrimination," he said.

As he had done the day before with the leaders of the European Union, Trudeau insisted on condemning the recent "appalling and appalling" terrorist attacks in France.

"It is unjustifiable and Canada wholeheartedly condemns these acts while standing with our French friends who are going through extremely difficult times," he said.

Three people were stabbed to death on Thursday in a church in Nice, in southern France, by a Tunisian man who was apprehended.

Anger erupted in the Middle East after the attacks against France and President Emmanuel Macron, vilified for having defended the right to publish the cartoons in France.

Macron made the comments during a tribute last week to Samuel Paty, a teacher beheaded in the street for showing caricatures of the Prophet Muhammad in class in a course on freedom of expression.

(With input from AFP)