Unknown thieves have stolen the cast iron entry gate featuring the infamous Nazi slogan “Arbeit macht frei” (“work sets you free”) from the former concentration camp Dachau, Süddeutsche Zeitung reports. The slogan is regarded as a symbol of the suffering of millions of prisoners.

German police announced in a statement that the theft took place in the early hours of Sunday morning. According to security personnel, the gate was still in place shortly before midnight. Investigators assume that criminals took the gate off of its hinges while security personnel were patrolling a different part of the site and escaped in a waiting vehicle.

A police spokesperson told journalists that it was too early to determine whether neo-Nazis or a “crazed collector” were responsible for the theft.

The outraged director of the Dachau memorial site, Gabriele Hammermann told Süddeutsche Zeitung “This is a new energy and form of desecration,” adding that the slogan on the gate was “the central symbol for the suffering of the prisoners.” Karl Freller, the director of the Foundation of Bavarian Memorials, labeled the theft as a “shameful deed.”

The Dachau concentration camp was opened by the Nazis in March 1933. Up until its closure in 1945, 41,500 people died at the site.

Comparisons are being made to the previous theft of the “Arbeit macht frei” slogan from the gates of the Auschwitz concentration camp in Poland five years ago. The perpetrators behind that theft were arrested only three days after the incident.