World War II Holocaust survivors gathered Tuesday in southern Poland to mark the 64th anniversary of the liberation of the Auschwitz Nazi death camp.
The United Nations January 27 anniversary has been designated as the annual Holocaust Remembrance Day.
Survivors, Polish government officials and foreign diplomats placed flowers and wreaths at camp monuments. More than one million people - most of them Jews - died in Auschwitz gas chambers, or through disease, forced labor or starvation.
Germany marked the day with a special session of parliament, where President Horst Koehler praised young Germans for seeking to learn about their country's wartime history as well as Holocaust victims.
Israel commemorates the Holocaust later this year in conjunction with the Hebrew calendar.
Italian lawmakers in Rome observed a moment of silence. Prime Minister Silvio Berlusconi then urged teachers and students to use the day to advocate the values of peaceful coexistence.
In Iran, where authorities routinely deny the Holocaust, officials marked the day with verbal attacks on Israel's recent treatment of Palestinians during its three-week military incursion into the Gaza Strip. Iranian government spokesman Gholam Hossein Elham referred to the Holocaust as a Zionist forgery.
Meanwhile, the Organization for Security and Cooperation in Europe expressed concern over increased expressions of anti-Semitism in the group's member countries. The organization, in a statement, called for intensified efforts to combat such acts.
Some information for this report was provided by AP.
