(JTA) — Unidentified passengers aboard a Belgian train used the speaker system to urge Jews to get off at Auschwitz and shower at the concentration camp.

The incident of Jan. 31 prompted the Belgian rail company SNCB to file a complaint with police over incitement to hatred, the RTL broadcaster reported Tuesday.

According to RTL, the suspects gained access to the speaker system during rush hour, at 5 p.m., while traveling from Namur to Brussels. One of the passengers said in French, “Ladies and gentlemen, we are approaching Auschwitz. All Jews are requested to disembark and take a short shower.”

The incident had been reported to Viviane Teitelbaum, a Jewish lawmaker in the assembly of the Brussels region.

Teitelbaum told RTL that the witness to whom she spoke suspected that members from a group of adolescents may have gained access to the keys that conductors use to make announcements over the loudspeakers.

A similar incident occurred in 2012 aboard the same line when the perpetrators, who were never caught, said, “Welcome to this train heading to Auschwitz. All Jews are requested to disembark at Buchenwald.”