Of the nearly 12 million students across the country, nearly 300 girls wore the long Islamic garment and were asked to change into something else. The vast majority complied and were allowed to return to class, however, 67 did not and were subsequently sent home.
According to the BBC, those who refuse to refrain from wearing the religious dress will be spoken to alongside their families by administrators. If the rule-breaking persists, they will be expelled.
The move to ban the abaya was announced by French education minister Gabriel Attal in August, and has since received mixed reviews. While some argue it infringes on personal liberties, many say the policy is in line with laïcité, France's unique brand of secularism which essentially bans religion from mixing with government in any way, including at state-run institutions.
Among other religious items banned are Christian crosses and Stars of David.
"When you walk into a classroom, you shouldn't be able to identify the pupils' religion just by looking at them," Attal said in justification of his decision to ban the abaya.
His sentiments were shared by President Emmanuel Macron. "Schools in our country are secular, free, and compulsory," he said. "They are secular because this is the very condition that makes citizenship possible, and therefore religious symbols of any kind have no place in them. We will vigorously defend this secularism."
Macron stated that French authorities would be "uncompromising" in their goal of stamping out displays of religiosity in public schools.
France has been a staunch defender of secularism even as changing demographics have led to increasing backlash against the policies.