Visitors to former Nazi concentration camps in Germany are being harassed by far-right activists, the head of two camps has warned.
The German government launched a crackdown on extremists and banned neo-Nazi group Combat 18.
Prof Volkhard Knigge, head of the memorial foundation for two of the most notorious camps, Buchenwald and Mittelbau-Dora, told of the harassment to the Neue Westfalische newspaper.
Prof Knigge said extremists had "targeted and prepared disruptions to guided tours”, and challenged guides on whether the Holocaust took place and the number of victims.
“There are increasing entries in our visitor books that describe national socialism and the concentration camps as useful and good for Germany,” he said.
“We even see anti-Semitic slogans or statements such as, ‘If the camps were still in operation, we would have no problem with foreigners’.”
World leaders gathered to commemorate the 75th anniversary of Allied Forces entering the Auschwitz concentration camp in January 1945.
Britain's Prince Charles, who was at the event, on Thursday said the "lessons of the Holocaust are searingly relevant to this day".
"Hatred and intolerance still lurk in the human heart, still tell new lies, adopt new disguises and still seek new victims," he said.
More than 56,000 people were killed in executions and experiments at the Buchenwald camp, which was the largest within Germany’s borders.
Mittelbau-Dora was a forced labour camp for factories and more than 20,000 died there.
On Thursday, Germany banned Combat 18 amid a resurgence of racist and anti-Semitic attacks that has prompted questions over how the country fights right-wing extremism.
In October, two people were killed in an attempted attack on a synagogue in the town of Halle in Eastern Germany.
Several high-profile German politicians have also reported receiving death threats from far-right groups in recent months.
