A public elementary school in Toronto was left nearly empty on Monday as parents protested against the province's new sex ed curriculum.

Between 200 and 300 protesters voiced their concerns with changes to the current sex ed system outside Thorncliffe Park Public School, said the CBC's James Murray. Toronto District School Board spokesman Ryan Bird said 1,220 of the 1,350 Grade 1 to Grade 5 students are not currently in class.

Meanwhile, across the city, the Toronto District School Board recorded 34,762 elementary school absences.

That's an increase of 144 percent compared to last Monday when there were 14,191 absences reported.

The board did not provide a breakdown of reasons for the absences, such as illness, etc.

In total, there are approximately 171,800 active elementary students at the TDSB.

A Thorncliffe parents' group is currently running a Facebook campaign called Parents & Students on strike: one week no school is encouraging parents who oppose the 2015 sex ed curriculum to keep their kids at home.

"We are sending them to have their science, math and English and whatever … we are not sending them for sex education," said parent Fatima Haqdad.

Thorncliffe Park has a large immigrant population. Immigrants with conservative or strong faith-based backgrounds have been among the most vocal critics of the province's new plan.

Education Minister Liz Sandals said she's disappointed that some parents have pulled their kids out of school, but vowed the curriculum would be in place by September.

Demonstrating parents at Thorncliffe Park said they'll protest again at that time.

They will be able to opt out of having their children attend the sex ed classes, though some school boards have questioned how they will be able to accommodate that should large numbers of students decline to take the class. 

With files from The Canadian Press