Kyrre Lien / EPA

Labour Party youth leader Eskil Pedersen speaks as thousands of people turn up in poor weather to participate in the singing of a popular children's song at Youngstorget Square in Oslo on April 26, 2012.

Reuters reports — Up to 40,000 Norwegians staged an emotionally-charged sing-along in Oslo on Thursday near the court house where Anders Behring Breivik is on trial for the murder of 77 people in a protest organizers said showed he had not broken their tolerant society.

"It's we who win," said guitar-strumming folk singer Lillebjoern Nilsen as he led the mass sing-along and watched the crowd sway gently in the rain. Many held roses above their heads, and some wept.

Norwegians to protest mass-killer, singing song he hates

The crowd chose to sing a song - "Children of the Rainbow" - that extols the type of multicultural society Breivik has said he despised and one that he specifically dismissed during the trial as Marxist propaganda. Read the full story.

Kyrre Lien / Scanpix via AFP -Getty Images

Kyrre Lien / EPA

Of the many people who turned up in poor weather to participate in the singing of "Barn av Regnbuen" ("Children of the Rainbow"), quite a few went on to place flowers for the victims near the entrance to the Oslo courthouse, where the trial of Anders Behring Breivik continued.

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Slideshow: Norway mourns after massacre

The nation looks to rally after a bombing and shooting spree leaves 77 people dead.

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Heiko Junge / Pool via AFP - Getty Images

Rightwing extremist Anders Behring Breivik, who killed 77 people in twin attacks in Norway last year, makes a salute as he enters an Oslo court on April 16, 2012.

Fabrizio Bensch / Reuters

Anders Behring Breivik has his handcuffs removed as he arrives for the first day of his trial.

Heiko Junge / AFP - Getty Images

Anders Behring Breivik sheds a tear as the court views a propaganda film he made before he carried out the deadliest attacks in post-war Norwegian history.

Fabrizio Bensch / Reuters

Members of the judiciary are pictured in the courtroom during the first day of the trial of Anders Behring Breivik.

Ian Johnston, msnbc.com reports — Anti-Islam militant Anders Behring Breivik admitted he had killed 77 people in a massacre last July, but said he was pleading not guilty to the criminal charges against him on the first day of his trial in Norway Monday, The Associated Press reported.

As he arrived in court - the early part of the session was broadcast on television - Breivik gave a salute, raising his arm with his first clenched.

He said that he did not "acknowledge the authority of the court." Read more.

Previously on PhotoBlog:

• Photo of Anders Behring Breivik minutes after arrest
• Portraits put a face on Norway massacre
• Security cameras captured images of Norway killer
• Norway killer reconstructs Utoya shooting spree for police

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Odd Andersen / AFP - Getty Images

Eskil Pedersen, second left, leader of the Labour party youth wing and Utoya survivor, is seated next to lawyer John Christian Elden, left, as they wait for the start of the trial.

Stoyan Nenov / Reuters

People look from inside a tram as they pass by the court in Oslo where the trial of Anders Behring Breivik is being held.

Slideshow: Norway mourns after massacre

The nation looks to rally after a bombing and shooting spree leaves 77 people dead.

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Ints Kalnins / Reuters

Survivor Alexandra Peltre (L) and her friend Andrea Markussen travel by boat to Utoeya island, northwest of Oslo on Monday, April 2, 2012.

Ints Kalnins / Reuters

Alexandra Peltre shows her escape route from the cafeteria at the island.

Reuters reports: She last saw Anders Behring Breivik when he raised his rifle at her on the shore of a small Norwegian island and calmly pulled the trigger. Now, 18-year-old Alexandra Peltre will face him in court as he stands trial for killing 77 people that summer's day. "I saw him right in the eyes, and poof! I had a hole in my leg," she said during a return to the wooded island where Breivik, an anti-Islam fanatic, killed 69 of his victims as they attended a Labour Party youth summer camp.

• Previous Utoya shooting posts on PhotoBlog.
• Full coverage of Oslo attacks and Utoya shootings.

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Ints Kalnins / Reuters

A view of the main house building at Utoeya island.

Ints Kalnins / Reuters

Alexandra Peltre sits at the shore where she was shot in the leg and hid in the water at the island.

AFP - Getty Images

A photo made available on Feb. 8, 2012 shows Anders Behring Breivik, the gunman who killed 77 people in twin attacks on July 22, 2011, sitting handcuffed and dressed as a police officer minutes after his arrest on Utoya island.

A photograph has emerged that was taken minutes after the arrest of Anders Behring Breivik, the right-wing extremist who has admitted killing 77 people in Norway's worst peacetime massacre. He is seen sitting handcuffed in a building on Utoya island, wearing police badges that appear to have been stitched on to his clothing.

Lise Aserud / Scanpix Norway via Reuters

Breivik arrives at a court hearing in Oslo on Feb. 6, 2012.

Breivik, who was detained by a police SWAT team on Utoya on July 22, 2011, told a court Monday that he deserves a medal of honor for the bloodshed and demanded to be set free. 

He has admitted detonating a fertilizer bomb that killed eight people at a government building in Oslo and hours later gunning down participants at a summer camp for Labor Party youths, killing 69.

Survivors and relatives of those killed wept and ridiculed Breivik as he defended his acts by issuing a tirade against immigration in his last scheduled detention hearing before the trial starts in April. 

"The way he talked, the way he smiled ... everything made me realize that no one has the same picture of the world as he does," said Helene Georgsen, 17, who survived Breivik's shooting spree.

--The Associated Press and Reuters contributed to this report

Previously on PhotoBlog:

• Security cameras captured images of Norway killer
• Norway killer reconstructs Utoya shooting spree for police

Slideshow: Norway mourns after massacre

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The AP reports:

Restrained by a harness, Anders Behring Breivik reconstructed his actions for police in a secret daylong trip back to the crime scene where he killed 69 people at Utoya island near Oslo.

The 32-year-old Breivik described the shootings in close detail during an eight-hour tour on the island with up to a dozen police, prosecutor Paal-Fredrik Hjort Kraby told a news conference in Oslo.

Trond Solberg / VG - Scanpix Norway via SIPA

Under heavily armored police guard, Anders Behring Breivik (left, in red T-shirt) returns to Utoya island on August 13 to reconstruct his actions during a shooting spree on the island.

Trond Solberg / VG - Scanpix Norway via SIPA

Breivik travels on the ferry under police guard.

The reconstruction took place amid a massive security operation that aimed to avoid escape attempts by Breivik and protect him against potential avengers. Breivik walked roughly the same route as the one he took during the shooting spree and explained what happened with as little interference as possible from police, Hjort Kraby said.

The entire hearing was filmed by police and may later be used in court, he added.

Trond Solberg / VG - Scanpix Norway via SIPA

Trond Solberg / VG - Scanpix Norway via SIPA

Breivik (top left, in red) leads police around the island.

Video images of the reconstruction published by Norwegian daily VG show Breivik arriving at Utoya with the same ferry he used to get to the island last month. Breivik wore a bulletproof vest and a harness connected to a leash over a red T-shirt and jeans as he casually led police around the island.

Breivik is seen pointing out locations along the way and simulating shots into the water, where panicked teenagers dove in to try to escape from him.

"The suspect showed he wasn't emotionally unaffected by being back at Utoya ... but didn't show any remorse," Hjort Kraby told reporters. Read the full story.

Trond Solberg / VG - Scanpix Norway via SIPA

Related content:

• Report: Teens threw stones at Norway mass killer
• Slideshow: Norway mourns after massacre

Matt Dunham / AP

People, including relatives of a victim in the center of the picture, gather to observe a minute's silence on a campsite jetty on the Norwegian mainland, across the water from Utoya island, where people have been placing floral tributes in memory of those killed in the shooting massacre on the island in Norway on Monday.

Emilio Morenatti / AP

A boy lights a candle to pay tribute to victims of Friday's twin attacks in central Oslo on Monday, July 25.

Paula Bronstein / Getty Images

Friends and loved ones gather at the Oslo cathedral to mourn the victims killed in twin terror attacks from a bombing in downtown Oslo and a mass shooting on Utoya island on Sunday in Oslo.

Related content:

• Norway lowers terror death toll, citing confusion on island after massacre
• Norway shooting victim played dead to survive
• German tourist rescued teens during massacre
• Slideshow: Norway in mourning after massacre
• More Oslo coverage on PhotoBlog