Update: Norwegian, 32, arrested over 'holiday island massacre' and linked to Oslo car bomb blasts. Norwegian police said at least 80 were killed at Utoya alone and described the killings as of 'catastrophic dimensions'. Police have said the attacks do not appear to be linked to Islamist terrorism but they are linking the two incidents. Initially, however, it was not known what the motives were - whether the gunman had been radicalised and was part of a militant Muslim group waging Jihad or was alternatively trying to further a home-grown political cause. The Oslo bomb blast was outside a government office, while the island of Utoya is reportedly owned by the Norwegian Labour Party. Teenagers on the Norwegian holiday island of Utoya had to 'swim for their lives' and hide in trees when the gunman fired indiscriminately at them. Around 700 had gathered on the island for a meeting of the youth wing of the ruling Labour party. Witnesses said the man in police uniform who opened fire beckoned several young people over before shooting at them. He told them to 'come here'.