Thousands of people have marched from the Auschwitz to Birkenau death camps in Poland to commemorate the six million Jews killed in the Holocaust.
Led by Israeli President Reuven Rivlin, many of the marchers were draped in Israeli flags as they walked the 3km path between the death camps on Thursday.
People across Israel also stood in silence for two minutes on Thursday as sirens blared. Traffic came to halt as drivers left their vehicles to take part in Holocaust Remembrance Day, Israel's most solemn day.
The march comes as Warsaw passed a controversial law setting out fines or jail time for those who blame the Polish people or state for atrocities committed by Nazi Germany during World War II.
Critics, including many in Israel, say the law is loosely formulated and could be abused to deny or negate Polish responsibility for crimes against the Jewish people.
The law is being reviewed by Poland's Constitutional Court.
Prime Minister Benjamin Netanyahu participated in a wreath-laying ceremony at the Yad Vashem Holocaust Memorial in Jerusalem on Thursday.
On the eve of Holocaust Remembrance Day, Netanyahu drew comparisons between the Nazi Regime and present-day Iran, issuing a stern warning to "not test the determination of the State of Israel."
Israel is concerned that its arch-rival Iran is boosting its military presence in Syria as the civil war there winds down.
"During the Holocaust, we were helpless, defenceless, and voiceless. In truth, our voice was not heard at all. Today we have a strong country, a strong army, and our voice is heard among the nations," the prime minister said.
But a senior Iranian official has warned Israel on Thursday not to provoke it following Netanyahu's warning to Tehran.
Ali Shirazi, an aide to Iran's supreme leader, was quoted by the semi-official Fars news agency as saying Iran is capable of destroying Israel.
He said: "if you provide an excuse for Iran, Tel Aviv and Haifa will be razed to the ground."
