French satirical weekly Charlie Hebdo published cartoons of the Prophet Mohammed nude on Wednesday.
Their offices are being guarded by riot police, as the magazine's front cover features an Orthodox Jew pushing the turbaned figure of Mohammed in a wheelchair.
There are concerns that the magazine may further anger Muslims, already outraged over an anti-Islamic film.
The offices of Charlie Hebdo were fire-bombed last year after the magazine published an edition entitled 'Sharia Hebdo' describing it as 'guest edited' by the Prophet Mohammed.
The French Foreign Ministry has announced plans to close up to 20 of its schools and embassies around the world on Friday, following concerns over a backlash against the publication of the cartoons.
They have also issued new travel advice, urging French people in the Muslim world to exercise "the greatest vigilance," avoiding all public gatherings and "sensitive buildings".