Norway's churches called for prayers and opened their doors to those seeking consolation and comfort as officials confirmed on Saturday that a suspected gunman killed at least 85 people at a youth summer camp after he allegedly set off a bomb blast that claimed the lives of seven people in Oslo, the capital.

"We pray for all those impacted (by the attacks) and for everyone now confronted with fear about what happened to their loved ones," said Bishop Helga Haugland Byfuglien of the main (Lutheran) Church of Norway. She added that local churches would receive suggestions for a united prayer, while Sunday services would also focus on the country's worst violence since World War II.

"The tragedy reminds us about our vulnerability. That (vulnerability) is faced by all people around the world. But we are not alone, God is with us. He gives hope and consolation."

- Bishop Helga Haugland Byfuglien of the Church of Norway

"The tragedy reminds us about our vulnerability," the bishop said in a statement. "That (vulnerability) is faced by all people around the world. But we are not alone, God is with us. He gives hope and consolation."

Yet, she acknowledged that "the brutal attacks" have changed Norway forever. "What has happened at (the island of) Utoya (where scores of youngsters were killed) directly influences our common future. I don't believe anyone imagined that young people, who gathered for discussions and relaxation, could be shot and killed."

Oslo's Catholic Bishop Bernt Eidsvig, meanwhile, said he was "linked in prayers" with all victims of the shootings and explosions.

Outside Norway, the World Council of Churches (WCC), said it was shocked about the violence. "At such moments the Norway's people and the government need the solidarity of the international community and the prayers of the Church around the world," added WCC's Secretary-General Rev Dr Olav Fykse Tveit, who is himself Norwegian.

In a message to Norway's Prime Minister Jens Stoltenberg and survivors, he said the "attacks against the fundamental institutions of a democratic society and young innocent people discussing political issues with each other shocked me deeply."

Rev Dr Tveit explained that he was "deeply saddened" about what had happened in his "beloved" native nation. "We have now experienced the reality of so many others around the world where violence disturbs the lives of innocent people."

He made clear that Christians around the world were praying that Norway, the home of the Nobel Peace Prize, would also in the future remain a state that is "open and filled with love and peace". He said it is crucial that churches support "a world of justice and peace without revenge, realising the values of democracy" while caring for "the rights and dignity of every human-being" as "all are made in the image of God."

Evangelical scholars argue however that attacks, such as in Norway, underscore the daily realities of a broken world and that all evil will eventually disappear only after Christ returns to earth.

The Norwegian bloodshed was also expected to be commemorated on Sunday by Christians across Europe, including in the Netherlands.

In the Dutch port city of Rotterdam the Norwegian seamen church will "open its doors the coming days to everyone seeking comfort following the events in Norway," said representative Havard Osland in published remarks.

Thousands of Norwegians live in the Netherlands; one in four are students, according to estimates.