Norwegians are marking the first anniversary of twin attacks that killed 77 people, the worst atrocity carried out in the country since World War II.

Commemorative events are scheduled across the country on Sunday, a year after 33-year-old Anders Behring Breivik set off a bomb near a government building in Oslo and then went on a shooting rampage on nearby Utoeya Island.

Breivik, on July 22, 2011, killed 69 people on the island, where the ruling Labour Party’s youth wing was hosting a summer camp. Eight people were killed in the blast in the capital earlier that day.

Numerous events are planned in and around Oslo, and especially at the sites of the two attacks, in memory of the victims.

Religious services and commemorative gatherings will also be held from the very south of the country to the Arctic archipelago of Svalbard, about 1,100 kilometres from the North Pole.

Norway’s Prime Minister reflects on massacre one year on

Prime Minister Jens Stoltenberg, who made a deep impression shortly after the massacre with his vow that Norway’s response to the bloodbath would be “more democracy, more openness and more humanity, but never naivety”, will be present at many of the events.

The Labour Party leader is scheduled to lay a wreath at the site of the Oslo bombing at 9:30 am (07:30 GMT) before attending, with Norway’s king and queen, a service at the city’s cathedral, which in the weeks after the attacks was surrounded by an ocean of roses left by mourners.

The Labour prime minister in neighbouring Denmark, Helle Thorning-Schmidt, is also scheduled to speak on Utoeya, while US Secretary of State Hillary Clinton has already delivered a message of sympathy to the Norwegian people for this “enormous tragedy”.

Eskil Pedersen, who heads the Labour Party youth wing and who escaped Utoeya at the beginning of the shooting massacre, last week hailed Norway’s reaction to the tragedy.

“There are … a few things that have developed in the right direction,” he told the NTB news agency, saying he was especially pleased that political youth groups had seen their membership numbers soar.

“We have more democracy now because more people are participating,” he said.

Breivik, whose 10-week trial ended last month, is meanwhile awaiting his verdict.

While there is no doubt he carried out the attacks, the five Oslo court judges must decide if he should be considered criminally sane and sentenced to prison, as requested by his defence, or instead follow the prosecution’s line and send him to a closed psychiatric ward.

The verdict should be announced on August 24.