Services of remembrance were held throughout Norway today, marking a month of mourning following the country's worst peacetime attacks in which 77 died.
At the Oslo Spketrum arena a tribute was paid to survivors, emergency services personnel and volunteers who took part in the rescue efforts.
In addition to speeches by Norway's King Harald and Prime Minister Jens Stoltenberg, the remembrance event was to include music acts including a one-off performance by Norwegian pop group A-ha, who officially disbanded in 2010.
A-ha had hits like Take on Me and The Sun Always Shines on TV.
Members of government, parliament, the royal family and dignitaries from Norway's Scandinavian neighbours were also due at attend. Among them the presidents of Finland and Iceland, the prime ministers of Denmark, Finland and Sweden, as well as the crown prince of Denmark and crown princess of Sweden.
Hundreds of survivors of the massacre at a youth camp on Utoya Island that claimed the lives of 69 people returned at the weekend for the first time to the scene of the killings.
Psychiatrists and medical staff were on hand to help those overcome by their pilgrimage to the place where Anders Behring Breivik shot dozens of their friends and colleagues during a 72-minute attack.
Almost half his victims were under 18. They were attending a summer camp for young supporters of the country's Labour party.
There were 517 survivors of the atrocity - 66 of whom were wounded. Many escaped by hiding among rocks and vegetation or swimming out into the lake around the island.
Norwegian television showed young people, dressed mostly in white, picking their way along Utoya's shoreline, possibly revisiting the spot from where they swam to safety or where friends were gunned down.
About 400 healthcare workers, police and other officials escorted them.
On Saturday, relatives of those killed travelled to the island and laid candles and flowers to mark where their sons, daughters or siblings were shot.
Breivik, 32, detonated a truck bomb outside government offices in Oslo, killing eight people, before his shooting spree on the island. Survivors and the families of the victims of the bomb visited the scene of the attack in Oslo yesterday.
He has admitted the killings but denies criminal guilt because he believes the massacre was necessary to save Norway and Europe. Norway's general director of health, Bjorn-Inge Larsen, said he hoped the visits would help the grieving process.
One survivor, Adrian Pracon, said returning to Utoya would be "an extremely emotional day". Pracon, 21, played dead on the shore to avoid being killed - at one point the gun was so close he could feel the warmth of the barrel.
Breivik aimed at Pracon's head and fired a shot. He missed and the bullet entered Pracon's left shoulder. Pracon said returning would be "something I really think I need".
He added: "I need to cry, I need to feel. I think I am still in denial. It will be good for me to do this process of trying to proceed with my life and realise that this has happened. It will help remember what actually happened."