Breivik was seen loitering around the site of the bomb blast in Oslo two hours before the island incident. The powerful bomb explosion which targeted the office of the Prime Minister Jens Stoltenberg occurred at 3.15pm. Most of the windows in the 20-floor building where the Prime Minister worked were shattered. The explosion started fires in the surrounding building and the streets in the area were filled with glass and debris following the explosion.
It caused widespread destruction to the oil ministry and several media outlets, including the state broadcaster and Norwegian tabloid newspaper VG. Following the explosion, police cleared the area and searched for any additional explosive devices.
Through media outlets citizens were urged to evacuate central Oslo. Police later announced that the bomb was composed of a mixture of fertilizer and fuel oil similar to that used in the Oklahoma City bombing. The Norwegian government was shook but the quick reaction from the police minimized the panic on site.
Utoya Island massacre
Unfortunately, national focus on Oslo bombing left Breivik with the opportunity to leave for Utoya Island, where the Norwegian Labor Party's annual youth summer camp was taking place. The 32-year-old tall Norwegian arrived on the island of Utoya dressed dressed as a policeman claiming to preform a routine check following the bombing event in Oslo.
The camp was attended by approximately 600 teenagers and former prime minister Gro Harlem Brundtland, whom Breivik said he hated and referred to in his writings as "the murderer of the nation", and they were all completely unaware that a mad gunman is among them. He asked people to gather around him before pulling weapons and ammunition from a bag and indiscriminately firing his weapons, killing and wounding numerous people. Breivik first shot people on the island and later started shooting at people who were trying to escape by swimming across the lake.
Survivors on the island described scenes of terror, unimaginable for a civilized person. Norwegian central counter-terrorist unit Beredskapstroppen was soon dispatched to Utoya from their headquarters in Oslo, but due to the unexpected circumstances they arrived almost an hour later. The terrorist surrendered almost immediately, leaving a bloody trail on the once peaceful holiday resort.