A Swedish far-right politician sparked controversy after claiming that Islamism poses a greater danger than the Nazis did.

Mattias Karlsson, of the anti-immigration Sweden Democrats, made the claims as the world was remembering the victims of Nazi genocide on Holocaust Remembrance Day.

"[Nazism] was quite a terrible threat, much worse in his time," Karlsson told state broadcaster SVT. "Today, I think that the threat of Islamism is perhaps greater than it is from Nazism. But one must of course take all ideologies seriously and fight them in every way."

"If you look at what is happening in the world right now, you cannot hide the fact that Islamism is a major threat to human rights and democracy throughout the world," added Karlsson.

The Sweden Democrats became the country's third most powerful party in last year's general election, winning 13% of the vote.

With its roots in Neo-Nazi subculture, in recent years it has tempered its extremist rhetoric, garnering support through anti-EU, anti-immigration and anti-Islam policies.

Karlsson's remarks drew criticism from Swedish Muslim and Jewish groups.

"As we make this commemoration, we want people to recognise evil in the world and to know that this can happen to any group, not just Jews," Lena Posner-Körösi, chairwoman of the Jewish community in Stockholm, told the Local.

"For [Karlsson] to talk about the threat of Islam as he has done is very dangerous and shows he hasn't learnt anything. And yes, he is from a group with a Nazi past."

Zachariah Zouhir who is chairman of the African Swedish National Association told the online newspaper: "He is seeking to polarise different groups. But actually what happened to the Jews is happening to Muslims now. We are being persecuted in Europe. We may not be being killed, but there are attacks on our mosques, women are being attacked in the street and governments are getting tougher on us."