Sirens wailed across Israel Thursday, as the country paid tribute to the six million Jewish people who perished in the Nazi Holocaust some 70 years ago.
For two minutes, pedestrians and traffic came to a standstill, and motorists stood next to their vehicles with heads bowed on one of the most solemn days on Israel's calendar.
In Poland, about 10,000 young people gathered for the "March of the Living" at Auschwitz, the most notorious of the German concentration camps. Those people were joined by some Holocaust survivors and U.S. military veterans who helped liberate the camps at the end of World War II.
Official events began late Wednesday with a ceremony at the Yad Vashem Holocaust memorial in Jerusalem.
At the ceremony, Israeli Prime Minister Benjamin Netanyahu linked the Nazi Holocaust to Iran's suspected efforts to build nuclear weapons. He said those who dismiss what he called the "Iranian threat" have learned nothing from the Holocaust.
Israel sees a nuclear-armed Iran as an existential threat and has been alarmed by statements by Iranian President Mahmoud Ahmadinejad to wipe the Jewish state "off the map."
Israel has threatened to take military action against Iran on its own if the international community fails to act.
Iran says its nuclear program is for peaceful purposes.