Israel has begun marking its annual Holocaust Memorial Day.

As is customary, sirens went off at 10am local time across the Jewish state and pedestrians and drivers came to a standstill, in memory of the six million Jews who perished during the Shoah.

A commemoration was held at Yad Vashem, the national Holocaust museum, on Wednesday night, with six survivors lighting torches in memory of the victims.

Yom Ha'Shoah remains a sombre day around the country, and nationally the Israeli flag flies at half-mast. Next week the country will again be united in a day of mourning, this time for Yom Hazikaron – the date when those who lost their lives fighting for Israel are remembered.

This year's proceedings were marred when a lighting rig collapsed during preparations for a service being held at Mount Herzl in Jerusalem. A woman, an officer in the IDF in her 20s, was killed and others were left with injuries in the disaster.

Speaking at the Yad Vashem ceremony, Benjamin Netanyahu said it would be ignoring the lessons of the Nazi era for Israel to ignore concerns about Iranian nuclear development.

"Our enemies tried to bury the Jewish future but our future was born again in the land of our forefathers, here we built a base, and a new beginning of freedom, and hope and action," he said.

"Those who dismiss the Iranian threat as a whim or an exaggeration haven't learned a thing from the Holocaust," said the Prime Minister.

"To be deterred from telling the truth - that today, like then, there are those who want to destroy millions of Jews - that is disrespectful of the Holocaust. That is an insult to its victims."

His comments were echoed by the Israeli President, Shimon Peres, who escaped Poland for what was then British Mandate Palestine before the Nazi occupation.

Accusing Iran of posing "a threat to world peace", Mr Peres said: "Humanity must learn the lessons of the Holocaust and face existential threats before it is too late."

Mr Peres also spoke movingly of having visited communities around Israel in recent weeks. "I thought about the communities from whence they came, and that are no longer with us. For a moment I replaced Tel Aviv with Vilna, Haifa with Białystok, Degania, Nahalal, Be'ersheva with Plonsk, Riga, and Odessa."

He also vowed that the one and half million non-Jews living in Israel would not "be discriminated against due to their nationality or religion".

He said: "That is the essence of the state of Israel. It is a protecting force, a safe haven, and a great spirit."

Israel is home to around 200,000 survivors of the concentration camps and other Nazi atrocities. Earlier this week the Israeli government pledged to improve support for those who were most vulnerable among them. An estimated quarter of survivors live below the poverty line.