Ten people dressed as Nazis staged a mock execution of a Jewish prisoner on the streets of a Dutch village in a reported protest against coronavirus restrictions.
Images on social media of the young people giving Nazi salutes and appearing to carry weapons caused outrage in Urk, which has the lowest vaccination rate in the Netherlands.
In one picture, a "Nazi soldier" pretends to shoot a kneeling person wearing the Star of David. The group were also accused of setting off a smoke bomb in the street on Saturday.
Authorities in the devout municipality are now investigating whether a crime was committed.
Local officials said the stunt was a protest against coronavirus restrictions. The group claimed to have been at a fancy dress party in a letter of apology sent on Monday, which made no mention of the pandemic.
It said: “We want to emphasise that we are absolutely not anti-Semitic or against Jews, or support the German regime. Our sincere apologies."
About three quarters of the Jewish population of the Netherlands, which was occupied by the Nazis during the Second World War, were murdered during the Holocaust.
“We understand that these young people want to make their voices heard about the impact of the current and upcoming coronavirus measures," mayor Cees van den Bos told the Nu.nl website.
"This discussion is not only taking place in Urk, but throughout our country. However, we do not understand the way they are doing it.
“As far as the municipality of Urk is concerned, with this tasteless action a very clear boundary has been violated,” the local authorities said in a statement.
Urk, where only 23 per cent of the adult population is fully vaccinated, is famously one of the most conservative Christian communities in the Netherlands.
Churchgoers in Urk attacked journalists in March. The media was reporting on people breaking coronavirus restrictions by continuing to attend church during the pandemic.
In January, there was an arson attack on a coronavirus test centre.