PARIS (Reuters) - An explosion rocked a kebab shop next to a mosque in Villefrance-sur-Saone in eastern France early on Thursday morning, a police source told Reuters.

"The window was blow out by an explosion in the night. The kebab shop was adjacent to a mosque," the source said, adding it appeared to be a criminal act.

French media reports said there were no wounded.

France was on high alert after hooded attackers on Wednesday killed 12 people at the Paris offices of Charlie Hebdo, a weekly known for lampooning Islam and other religions, in the most deadly militant attack on French soil in decades.

(Reporting by Catherine Lagrange; writing by Andrew Callus; Editing by John Irish)