A solemn commemoration is to be held in Oslo Sunday, one month after the double July 22 terrorist attack that left 77 persons dead.

In the afternoon hours Friday, July 22, a bomb went off nearby central government buildings in downtown Oslo, killing 8 persons.

Soon after, a shooter disguised as a policeman opened fire at a youth camp of ruling Norwegian Workers' Party, killing 69, most of them teenagers.

Anders Behring Breivik, a 32-year-old of Norwegian ethnicity, was apprehended soon after and confessed perpetrating both atrocities.

He had published a 1,500-page manifesto on the internet shortly before, revealing him to hold radically Christian, far-right, anti-multiculturalist and anti-Marxist beliefs.

Breivik has styled himself as a Crusader and described what he did as "atrocious but necessary" to draw attention to the threat coming to Europe from other cultures, and from within in the guise of multiculturalists and leftists.

Sunday afternoon a solemn procession and concert will be held in the Norwegian capital, with speeches by King Harald V and PM Jens Stoltenberg.

Representatives of the royal families of neighboring Denmark and Sweden, the presidents of Iceland and Finland, as well as Scandinavian PMs will also be present at the commemoration.

Saturday survivors of the Utoya massacre had the opportunity to visit the place of their ordeal for the first time after the July event, an opportunity that was given Friday to relatives of the killed.

Meanwhile, the court extended Christian fundamentalist's strict incarceration for another four weeks.