(JTA) — A French municipality launched a probe into an elementary school’s use of red and yellow tags to identify pupils who do not eat pork and meat, respectively.

The city of Auxerre, located 105 miles southeast of Paris, opened the investigation on Friday after parents complained to local media about the school’s initiative, in which neck strings bearing red and yellow plastic discs were placed on pupils ahead of lunchtime at the school cafeteria.

The pupils wore the tags for one day before the faculty was instructed to stop using them.

The debate on the availability in public schools of pork-free dishes is a divisive issue in France, where rightist parties and other politicians advocating strict separation between religion and state see it as proof of a creeping influence on the public sphere, mostly by Muslims immigrants.

Malika Ounes, a conservative member of the Auxerre city council, told the news website Creusot-Infos.com: “It’s revolting. It brings back memories of dark times,” in reference to the requirement in Nazi-occupied France that Jews wear yellow stars on their clothes.

Among the pupils instructed to wear the tags were Muslims and vegetarians. Reports in French media did not mention any Jewish pupils.

Some parents also complained about the tags, whose use Mayor Guy Perez of the Socialist Party termed “unfortunate.”

But other parents said they were the result of good intentions.

One Muslim mother of two boys attending the school, identified by the RTL broadcaster only as Sonia, said: “The yellow tag doesn’t even correspond with the yellow star. I don’t think there’s a scandal here, just an error that doesn’t require all this rebuke.”

CRIF, the umbrella group representing French Jewish communities, has remained neutral in the debate about pork in cafeterias, largely because observant Jews refrain from eating anything that doesn’t comply to kashrut standards, whether it contains pork or not.

But French Chief Rabbi Haim Korsia in March weighed in on the debate, labeling the removal of pork-free dishes “heresy that contradicts the separation of religion and state.”