Several thousand people, including hundreds of Greek Orthodox clerics, have marched on parliament, angry about new school texts they claim endanger faith in Orthodox Christianity.
Some participants at the Athens event on Sunday held banners that denounced the authors as traitors to the country or read: “No to ecumenical religion.”
The new textbooks devote more space to other Christian denominations and different religions that received mostly a cursory and rather negative treatment in past texts.
Religious instruction is taught in each of the 12 grades that make up Greece’s primary and secondary education systems.
Protesters delivered a petition to parliament before disbanding peacefully.