Up to 150,000 Norwegians gathered in Oslo with red and white roses on Monday to show solidarity with the 76 people who were killed in attacks on a government building and a political youth camp.
The 'rose march' was held in a spirit of mourning but also one of support. Musicians performed at a concert after a moment of silence was extended to a full five minutes as those gathered held their flowers aloft in remembrance.
Members of the royal family including Crown Prince Haakon and his wife Princess Mette-Marit, and the prime minister, Jens Stoltenberg, and his wife Ingrid, joined the crowds.
"Tonight the streets are filled with love," said Price Haakon.
Rallies were also held in other cities in Norway after a national moment of silence.
Earlier, Anders Breivik, the man who has confessed to the killings, claimed "two more cells" were working with him.
The 32-year-old made the claims before a closed court hearing on Monday, where he also admitted carrying out the attacks, but entered a plea of not guilty.
He told the court he wanted to save Norway and Western Europe from "cultural Marxism", and accused the Norwegian Labour party of allowing "mass imports of Muslims" into the country, Judge Kim Heger said.
The Oslo court decided to hold the hearing in private after online campaigners petitioned for a media blackout.
If convicted, Breivik's maximum time in jail would be just 21 years. However it is possible under Norwegian law for his sentence to be extended if he is deemed a threat to the public.
Police said they would be conducting an investigation into their response to the twin attacks, after they were criticised for sending a car, not a helicopter, to Utoeya.
Meanwhile, police revised down the killings at the Labour camp party on the island of Utoeya to 68, and increased the death toll from the bomb blast in central Oslo to eight, bringing the total to 76.