One policeman and three civilians were killed in the protests in Zinder after Friday prayers, a police source told Reuters.
“Some of the protesters were armed with bows and arrows as well as clubs. The clashes were very violent in some places,” the source added.
Agence France-Presse quoted a minister as saying dozens of people had been injured.
Local residents told Reuters that demonstrators had set fire to churches and raided shops that were run by Christians.
“The protesters are crying out in local Hausa language: Charlie is Satan – let hell engulf those supporting Charlie,” a local shopkeeper said by telephone.