ATHENS (AP) — About 2,000 people have marched to the Greek parliament to protest new school books they claim endanger faith in Orthodox Christianity, Greece's official religion.

The protesters on Sunday included many Greek Orthodox priests and bishops. Some participants at the Athens event held banners that denounced the book authors as traitors to the country or read, "No to ecumenical religion."

They delivered a petition to parliament before disbanding peacefully.

Religious instruction is taught in each of the 12 grades that make up Greece's primary and secondary education systems.

The new textbooks, especially for the upper classes, devote more space to other Christian denominations and other religions that received mostly a cursory and rather negative treatment in past texts.