Police arrived at the Norway island massacre an hour and a half after a gunman first opened fire, because they did not have quick access to a helicopter and could not find a boat to get to the scene just several hundred yards offshore, it has emerged.

A gunman who opened fire on an island teeming with young people kept shooting for an hour and a half before surrendering to a SWAT team which arrived 40 minutes after they were called, police in Norway said today.

Norwegian bomb disposal teams were searching for unexploded devices today on the island where an attacker opened fire, killing around 10 people attending a youth camp.

More than 25 people were feared dead tonight after a bomb ripped open buildings in the heart of Norway's government and a man dressed as a police officer opened fire at an island youth camp connected to the ruling party.