Thousands of people gathered in communities across the country Sunday to remember the six million Jews killed by Nazis during the Second World War.

Canada's Jewish communities have taken part in similar ceremonies for decades, but this year the federal government formally acknowledged worldwide Holocaust Remembrance Day for the first time. Last fall, Parliament added the date to the official commemoration calendar.

"For 60 years, Jews have been screaming and yelling, 'never again, never again,' said Rabbi Asher Jacobson in Montreal.

"And what greater way to say never again than to say that we're still Jews, we're still proud to stand as Jews and we'll go out into the street and say, 'we'll continue on.'"

There were candles, choirs and quiet moments of prayer and reflection in many cities, as well as a vow to never forget the horrors of genocide.

In Halifax, volunteers took turns reading out thousands of the names of people murdered.

"I think it will make people more aware," said one woman, especially hearing the ages of victims as young as two. "It's very sad, and I think people will listen."

In Toronto, about 2,000 people gathered in a park in what organizers said was the largest Holocaust Remembrance Day ceremony of its kind outside of Israel.

In Ottawa, Justice Minister Irwin Cotler and Conservative Leader Stephen Harper were among dignitaries at a ceremony next to the Centennial Flame on Parliament Hill.

Some people said this year's ceremonies have taken on even greater importance given recent vandalism of Jewish homes and cemeteries in Toronto, and an attack of arson at a Montreal Jewish school.

"Never again, will we be indifferent to killing fields, ethnic cleansing and genocide," Cotler told the crowd. And he reminded people that tolerance must be universal, since all races and religions can be perpetrators as well as victims.

"The Holocaust did not begin in the gas chambers. It began with words," he told reporters later. "These are the catastrophic effects of racism."