Some students born in 2010 will have started secondary school for the first time this autumn. The hashtag #anti2010 had more than 40 million views on TikTok before it was removed.
"The warm welcome of sixth-grade students -- and their successful integration thanks to the goodwill of their peers and adults -- is an essential issue in school life at the college," Blanquer said in a letter on Thursday evening.
Families could report such harassment on an emergency hotline, he said, adding that any pupil behind such cyberbullying would be punished.
Blanquer also stated that a "worrying movement" of online harassment is reported by education facilities at the start of the new school year.
"A new phenomenon that has recently appeared on the social networks TikTok and Twitter that encourages insults and threats by older peers towards children born in 2010," he continued in his letter.
"While many children do not use the platforms, for those who do, it is clear that their mental and psychological health is in real danger."