"The attacks give cause for us to reflect whether we should have expressed ourselves in a different way," Stoltenberg said. "That goes for politicians, for journalists, the office canteen and for the internet."
The popularity of Norway's Prime Minister, who is a member of the Labour Party, has hit highs since the Olso bombing, which claimed eight victims, and the subsequent Utoya island massacre, in which 69 Labour youth members were killed.
Anders Breivik, the 32-year-old self-confessed far-right perpetrator had accused the Labour Party of promoting "Muslim world domination".
In a 1500-page manifesto he put online just before the attacks, he claimed his actions were part of a crusade that would purge Europe of Muslims and "cultural Marxists" by 2083.
In contrast to Stoltenberg and his Labour Party, the popularity of Norway's right-wing, anti-immigrant Progress Party has plummeted after the attacks. Breivik was a Progress member for more than a decade before he left the organisation, claiming it was not radical enough.
Norway's King Harald V and victims' relatives attended yesterday's parliamentary session, where the names of those killed were read out.
Stoltenberg declared a national day of mourning would be held on August 21 to commemorate the victims of the worst act of violence Norway has experienced since World War II.
Investigators said they are almost certain that Breivik acted alone. But they were searching his computer and mobile-phone data for possible links with far-right groups.
The young Labour youth members killed in the Utoya island massacre had come from throughout Norway to attend a summer camp on the island, 56km northwest of Olso. Yesterday, Turkey's Foreign Minister travelled to Trondheim to attend the funeral of the Norwegian immigrant Gizem Dogan, 17, who was shot and killed at Utoya. Gizem was described as being "colourful in every way".
- Independent