Millions of Israelis paused for two minutes Monday in solemn silence as air raid sirens wailed across the country to mark Holocaust Remembrance Day.

The annual commemoration for the 6 million Jews killed in Europe during the Holocaust brought the country to a standstill at 10 a.m., with drivers standing alongside their cars on highways and normally bustling city centers freezing for the funereal event.

After the sirens, a number of remembrance ceremonies were planned for across the country, including a wreath-laying at the Yad Vashem Holocaust memorial in Jerusalem and the “Unto Every Person There is a Name” ceremony at the Knesset.

In Poland, thousands of Israeli and Jewish youth and others will march from the infamous Auschwitz labor camp to the Birkenau death camp as part of the annual March of the Living memorial.

Events for the commemoration day began Sunday night at 8 p.m. with a state ceremony at Yad Vashem.

Prime Minister Benjamin Netanyahu warned at the ceremony that the world was ignoring the lessons of the Shoah by allowing Iran to continue its nuclear program.

“I hope that the lessons of the past will be learned and that the desire to avoid confrontation at any cost will not lead to a deal that will exact a much heavier price in the future,” he said, referring to negotiations between Tehran and six world powers over uranium enrichment levels. “I call on the leaders of the world powers to insist on a full dismantling of Iran’s capability to manufacture nuclear weapons, and to persist until this goal is achieved.”

President Shimon Peres, speaking at the same ceremony, called on the world to pay attention to the threat of rising anti-Semitism in Europe.

“We must not ignore any occurrence of anti-Semitism, any desecration of a synagogue, any tombstone smashed in a cemetery in which our families are buried,” he said. “We must not ignore the rise of extreme right-wing parties with neo-Nazi tendencies who are a danger to each of us and a threat to every nation.”