In this condolence text the Secretary-General said the shooting of children and youth attending the summer camp at Utøya was particularly disturbing.
"The targeting of young people who worked only to contribute to the future of their country is particularly heinous. On behalf of the UN I extend my deepest condolences to the families and loved ones of those who died. I commend Prime Minister Stoltenberg for his leadership and healing touch."
Mr. Ban went on to offer some words of comfort for the people of Norway.
“At a time of national grief, I am confident that Norway's traditions of tolerance and mutual respect will see the country through this difficult passage".
Hundreds of people have signed the book of condolences at the Norwegian Consulate General in New York. Thousands more have done so at Norwegian Embassies and Consulates around the world.
In addition, anyone who wishes to express their sympathy is welcome to write a message in Norway’s official online book of condolences.