The UN Friday organised a memorial ceremony to commemorate the victims of the Holocaust, with a particular focus on child victims.

The memorial ceremony was held on the annual International Day of Commemoration in Memory of the Victims of the Holocaust.

This year's theme was "Children and the Holocaust".

"This year's international day is dedicated to children -- girls and boys who faced terror and evil," UN Secretary General Ban Ki-moon said in a video message.

The Holocaust was a genocide perpetrated by Nazi Germany against Jews and other minority groups who were often imprisoned in concentration camps before being executed.

Some six million Jews and hundreds of thousands of other minorities as well as handicapped people were killed in the Holocaust.

The toll included 1.5 million Jewish children and tens of thousands of handicapped children and children from Roma and Sinti groups.

"Many were orphaned by the war or ripped away from their families," Ban said. "Many died of starvation, disease or at the hands of their abusers. We will never know what these children might have contributed to our world."

Nassir Abdulaziz Al-Nasser, president of the UN General Assembly delivered a speech at the ceremony that called on the international community to honour Holocaust victims by making sure that such atrocities never happen again.

Children themselves can do much to help combat racism and intolerance, he said.

"Youth can play an important role in efforts to advance cross-cultural understanding and dialogue.

"In partnership with the Alliance of Civilizations, I intend to organize on March 22 an interactive thematic debate of the General Assembly on this vital topic," he added

"Today, as we remember all those lost during the Holocaust -- young and old alike -- I call on all nations to protect the most vulnerable, regardless of race, color, gender or religious beliefs, " Ban said.