The Norwegian prime minister, Jens Stoltenberg, has told a remembrance service for the 76 people killed by Anders Behring Breivik that his country had been "struck by evil", but urged his countrymen to respond by embracing democracy and freedom.

Speaking as the first funerals were held for victims of Breivik's bomb and shooting attack, Stoltenberg said the 32-year-old's actions were "an attack against political engagement … an attack on our democracy".

He added: "We have memorials in churches and in mosques, in parliament and in the government headquarters, on the streets and in squares … Evil has brought out the best in us. Hatred engenders love."

While the prime minister was speaking, police questioned Breivik for the second time. Officers said they had now identified all of those killed in the bomb and gun attacks, adding a new list of victims would be released later.

Two psychiatrists have been appointed to assess Breivik's mental health.

Investigators believe the 32-year-old acted alone, after years of meticulous planning, and have not found anything to support his claims of being part of an anti-Muslim militant network plotting a series of attacks across Europe.

Breivik was questioned for seven hours last Saturday, the day after the twin attacks, which targeted the government district in Oslo and a Labour party youth camp. He admitted carrying out the attacks but has pleaded not guilty to terror charges, saying he is in a "state of war", according to his lawyer and police.

Police have charged Breivik with terrorism, which carries a maximum sentence of 21 years in prison. However, it is possible the charge change during the investigation to crimes against humanity, which carries a 30-year sentence, Norway's leading prosecutor, Tor-Aksel Busch, told the Associated Press."Such charges will be considered when the entire police investigation has been finalised," he said. "It is an extensive investigation. We will charge Breivik for each individual killing." A formal indictment is not expected until next year.