Israelis across the nation paused in memory of the six million Jews killed during the Holocaust, as a siren sounded throughout Israel on Monday.

The theme of this year's commemoration is "Fragments of Memory: The Faces Behind the Documents, Artifacts and Photographs."

The central ceremony commemorating Holocaust Remembrance Day is to take place at the Yad Vashem Holocaust memorial in Jerusalem.

Israel's observance of Holocaust Remembrance Day lasts until Monday sundown.

Ahead of this year's Holocaust Remembrance Day, Yad Vashem announced it was launching a nationwide effort to collect documents, diaries, photographs, artwork and other items from the time of the Holocaust in the possession of individuals, so that they can be documented and preserved for future generations.

The Holocaust authority is also launching a virtual memorial wall on Facebook, which will allow visitors to post the names of those who perished in the Holocaust.

The victims' names will then link to any information about them in the Yad Vashem database. The four millionth name, of the six million Jewish victims of the Holocaust, was added to the database several months ago.

The names have been provided over the years based on testimony provided by victims' friends and relatives, through wartime records, and from other sources, such as memorial walls in synagogues. The efforts to complete the list are ongoing.