At least 10 people have been killed in violent protests in the West African nation of Niger over the French satirical weekly Charlie Hebdo's depiction of the Prophet Muhammad, the country's president said.

President Mahamadou Issoufou said five deaths were reported after demonstrations in Niamey, the capital, on Saturday. Another five people died on Friday in the town of Zinder following prayer services there. The victims were inside churches and bars that were set ablaze, he said.

The violence erupted after Charlie Hebdo published its first issue since the Jan 7 attack on its headquarters by Islamic extremists that left 12 people dead.