WARSAW, Poland — The world marked International Holocaust Remembrance Day on Sunday amid a revival of hate-inspired violence and signs that younger generations know less and less about the genocide of Jews, Roma and others by Nazi Germany during World War II.

As survivors of Auschwitz marked the 74th anniversary of the notorious death camp's liberation, a far-right activist who served time in prison for burning an effigy of a Jew placed a wreath there with about 50 other Polish nationalists to protest the official observances.

Piotr Rybak said the group opposes the annual ceremony at Auschwitz to mark the camp's liberation by the Soviet army, the event that gave rise to the international Jan. 27 remembrance. Rybak claimed it glorifies the 1 million Jewish victims killed at the Auschwitz-Birkenau death complex and discounts the 70,000 Poles killed there.

Rybak's claim is incorrect. The ceremony at the state-run memorial site paid homage Sunday, as it does every year, to all of the camp's victims, both Jews and gentiles, while Christian and Jewish religious leaders recited a prayer in unison together.

Since last year's observances, an 85-year-old French Holocaust survivor, Mireille Knoll, was fatally stabbed in Paris and 11 Jews were gunned down in a Pittsburgh synagogue during Shabbat services.

Human Rights First, a U.S. organization, recalled those killings and warned that "today's threats do not come solely from the fringe."

"In places such as Hungary and Poland, once proudly democratic nations, government leaders are traveling the road to authoritarianism," said Ira Forman, the group's senior adviser for combating anti-Semitism. "As they do so, they are distorting history to spin a fable about their nations and the Holocaust."

Former Auschwitz prisoners placed flowers early Sunday at an execution wall at Auschwitz. They wore striped scarves that recalled their uniforms, some with the red letter "P," the symbol the Germans used to mark them as Poles.

Early in World War II, most prisoners were Poles, rounded up by the occupying German forces. Later, Auschwitz was transformed into a mass killing site, operating until the liberation by Soviet forces on Jan. 27, 1945.

In Germany, Foreign Minister Heiko Maas warned in an op-ed in the weekly Welt am Sonntag that across Europe populists are propagating nationalism and "far-right provocateurs are trying to downplay the Holocaust."

"We shall never forget. We shall never be indifferent. We must stand up for our liberal democracy," Maas wrote.

However recent surveys show that knowledge of WW II atrocities is declining generally.

A new study by the Conference on Jewish Material Claims Against Germany and the Azrieli Foundation found that 52 percent of millennials in Canada cannot name even one concentration camp and 62 percent did not know that 6 million Jews were killed in the Holocaust.

Its findings were similar to a similar study carried out a year before in the United States.