An explosion in the Norwegian capital on Friday left eight dead and many injured. A bomb went off near the prime minister’s office in the late afternoon. Soon after, the perpetrator killed dozens of youngsters gathered for a Labor Party summer camp on a small island west of Oslo where former prime minister Gro Harlem Brundtland had just spoken. The killer identified her as his primary target on Monday.

Prime Minister Jens Stoltenberg was scheduled to speak at the island on Saturday. He was not in office during the blast and remained unharmed as did Brundtland but at least 68, many of them teenagers, perished in a killing spree.

Police detained the gunman who was described as tall, blond and a right-wing extremist. The 32 year-old criticized “cultural Marxists” in a lengthy essay that he had posted online and championed a “crusade” against Islam in the Scandinavian country. He blamed the Labor Party for letting Muslims “colonize” Norway and accused it of “treason.”

Police believe the gunman drove to the island after the explosion in the capital.

This post was updated with corrections and new information.