Fifty-six years after British troops helped liberate Nazi concentration camps, survivors, politicians and community leaders have gathered in London to remember the victims of genocide.

Britain's first Holocaust Memorial Day, coinciding with memorial days in Germany, Italy and Sweden, was marked at Westminster Hall in central London.

The ceremony, which was broadcast live on BBC Two and BBC Radio 4, was attended by Prime Minister Tony Blair, Chief Rabbi Jonathan Sacks and Prince Charles.

Princes Charles represented the Royal Family at the ceremony

It began with the lighting of a commemorative flame by a six-year-old refugee from Kosovo, and the reciting of a poem by actress Emma Thompson.

Mr Blair told the ceremony that the Holocaust was the greatest act of collective evil the world had known.

"What made the Holocaust so frightening was its goal, its unimaginable scale and its wickedness in attempting to use false science to further human destruction," he said.

"It is to reaffirm the triumph of good over that evil that we remember it."

Genocide

Bob Geldof paid tribute to the British "righteous" who saved Jewish lives, saying: "They became through their deeds our living conscience.

"If we all behaved as them, genocide would be a crime of the past and not the contemporary sickness we still bear witness to."

Actor Sir Ian McKellen spoke of the plight of the unknown number of homosexuals and other minorities killed in the camps.

Another actor, Sir Anthony Sher, spoke of other genocides in Cambodia, Rwanda and Bosnia.

We cannot pass by, but resist the oppressive state, the foul tyrant and the murderous racisms Bob Geldof

The audience listened in silence as concentration camp survivors Roman Halter and Esther Brunstein gave a harrowing account of their experiences.

Mr Halter told of the moment when the slaughter began near his home, saying: "I heard shots... I saw my Jewish friends being used as target practice.

"One of the SS recruits was a boy from school - we had played together."

Mrs Brunstein said: "It was like a world gone mad."

As well as the Holocaust, there was also recognition of genocide in Cambodia, Rwanda and Bosnia-Hercegovina, but the Turkish massacre of thousands of Armenians in 1915 was not included.

The day of remembrance marks the anniversary of the liberation of the Auschwitz concentration camp on 27 January, 1945.

Survivors invited

The ceremony at Westminster City Hall featured a broadcast of Richard Dimbleby's famous BBC radio broadcast at the liberation of Belsen.

He described seeing thousands of naked bodies and the smell of rotting flesh as he entered.

The starved prisoners of war had slit open the bodies of their dead compatriots to eat their kidneys and livers, such was the extent of the starvation, he said.

Prince Charles attended the ceremony to light a candle in remembrance.

Home Secretary Jack Straw, Conservative Party leader William Hague, Liberal Democrat leader Charles Kennedy and the leaders of all Britain's main churches were among the congregation.

Holocaust Memorial Day marks the anniversary of the liberation of Auschwitz

Some 200 survivors of Nazi concentration camps and survivors of the century's other atrocities also attended.

From the Armenian community in Britain, its church's spiritual leader here, the Right Reverend Nathan Hoviharnissian, was present.

There have been protests about the remembrance day from some Armenians, who feel their suffering is still being ignored.

The Armenians were the victims of what they say was genocide by the Ottoman Empire between 1915 and 1917.

They estimate the Turks wiped out between 1.1 million and 1.8 million out of a population of 2.8 million, but the issue is hugely sensitive and the facts remain in dispute.

Scottish First Minister Henry MacLeish and the Secretary of State for Scotland, Helen Liddell, attended a simultaneous event at Edinburgh's Usher Hall.

Countrywide events

Other events were organised all over the country for what will become an annual event.

In Leeds a ceremony of remembrance and a one-minute silence will be held in Victoria Gardens on Sunday, followed by a candle-lit procession to the Civic Hall.

A free exhibition commemorating innocent victims murdered in the last 100 years opened at Carmarthenshire County Museum, south Wales, with children across Torfaen planting commemorative snowdrops.

Residents of Cardiff came together at a special National Memorial Service at Cardiff City Hall on Friday night with a multi-faith service at the Temple of Peace on Sunday.