TORONTO -- A parents' campaign to keep kids out of class to protest Ontario's new sexual-education curriculum has decimated attendance at at least one Toronto-area school.

A spokesman with the city's public school board says more than 60 per cent of students attending Thorncliffe Park Public School are absent today.

Ryan Bird says 825 of the 1,300 Grade 1 to Grade 5 students are not currently in class, adding about 100 parents are also protesting outside the building.

Many opponents of the province's new curriculum have been objecting to its contents on religious grounds, saying lessons involving sexual orientation, gender identity and masturbation don't align with their faith-based values.

The Thorncliffe Park community is widely known to have a large Muslim population.

The updated curriculum is set to take effect in September.