Some 400 people made a remembrance march in Krakow to mark the 70th anniversary of the liquidation of the Polish city's Jewish ghetto.
The marchers on Sunday walked from Ghetto Heroes Square to the site of the former concentration camp at Plaszow.
"There are voices in the world that say it was all not true, that it was impossible to kill 6 million people," Israeli Ambassador to Poland Zvi Rav-Ner said during the ceremony. "Therefore, it is important to remember what happened. From this square in Krakow should go out into the world the message that such crimes cannot happen again."
Tadeusz Jakubowicz, the president of the Krakow Jewish community, said the Nazis wanted to humiliate the Jewish community and started the liquidation of the ghetto on a Saturday, a few days before Passover.
The Krakow ghetto was among the largest in Poland's general government, which was under Nazi rule from 1939 to early 1945. In March 1941, 17,000 people lived there. The Nazis transported them to the camps at Belzec, Plaszow and Auschwitz.