SUNDVOLLEN, Norway (AP) - The Norwegian man suspected in a bombing and shooting spree that killed at least 92 people bought six tons of fertilizer before the massacre, the supplier said Saturday as police investigated witness accounts of a second shooter.
 
Norway's royal family and prime minister led the nation in mourning, visiting grieving relatives of the scores of youth gunned down at an island retreat, as the shell-shocked Nordic nation was gripped by reports that the gunman may not have acted alone.
 
The shooting spree began just hours after a massive explosion that ripped through an Oslo high-rise building housing the prime minister's office. At least 91 people have been killed, but police say more are missing.
 
The queen and the prime minister hugged when they arrived at the hotel where families are waiting to identify the bodies. Both king and queen shook hands with mourners, while the prime minister, his voice trembling, told reporters of the harrowing stories survivors had recounted to him.
 
A man who said he was carrying a knife was detained by police officers outside the hotel. He told reporters as he was led away that he was carrying the weapon because he didn't feel safe.
 
On the island of Utoya, panicked teens attending a Labour Party youth wing summer camp plunged into the water or played dead to avoid the assailant in the assault that may have lasted 30 minutes before a SWAT team arrived, police said. A picture sent out on Twitter showed a blurry figure in dark clothing pointing a gun into the water, with bodies all around him.
 
Prime Minister Jens Stoltenberg said the twin attacks made Friday peacetime Norway's deadliest day.
 
Buildings around the capital lowered their flags to half-staff on Saturday. People streamed to Oslo Cathedral to light candles and lay flowers. The Army patrolled the streets of the capital, a highly unusual sight for this normally placid country.
 
"This is beyond comprehension. It's a nightmare. It's a nightmare for those who have been killed, for their mothers and fathers, family and friends," Stoltenberg told reporters earlier Saturday.
 
The suspect in police custody - a blonde blue-eyed Norwegian with reported Christian fundamentalist, anti-Muslim views - has been preliminarily charged with acts of terrorism.
 
Information about the man began to trickle out Saturday, including that he owned a farm and had amassed six tons of fertilizer in the weeks before the twin attacks. Fertilizer is highly explosive and can be used in homemade bombs.
 
Oddny Estenstad, a spokeswoman for agricultural material supplier Felleskjopet, said Saturday that the company alerted police to the purchase after the man emerged as a suspect.
 
That quantity of fertilizer - akin to 200 50-pound bags of grain - wouldn't have fit in one car, according to Bob Ayers, former U.S. intelligence official. Two burned-out cars could be see at the scene Friday, but police have not confirmed whether they were used in the attack.
 
Though police did not release his name, Norwegian national broadcaster NRK identified him as 32-year-old Anders Behring Breivik and said police searched his Oslo apartment overnight.
 
Foreign Minister Jonas Gahr Stoere told reporters that the attacks, believed to be the work of a man who has posted on Christian fundamentalist websites, showed you can't jump to conclusions about terror acts. He said most of the political violence that Norway has seen has come from the extreme right.
 
"This is a phenomenon that we have to address very seriously," Stoere said.
 
The Army patrols were an indication of the stepped up vigilance, although police lifted their recommendation, issued after the bombing, that people stay away from the city center.
 
Gun violence is rare in Norway, where the average policeman patrolling in the streets doesn't carry a firearm. Reports that the assailant was motivated by political ideology was shocking to many Norwegians, who pride themselves on the openness of their society.
 
Andresen, the acting police chief, said the suspect was talking to police.
 
"He is clear on the point that he wants to explain himself," he told reporters at a news conference.
 
The toll in the shooting hit 85 on Saturday, but police warned that it could rise further as they sent divers into the lake around the island retreat to look for bodies. Acting Police Chief Roger Andresen said he did not how many people were still missing.
 
The Oslo University hospital said it has so far received 11 wounded from the bombing and 16 people from the camp shooting.
 
The carnage began Friday afternoon in Oslo, when a bomb rocked the heart of Norway. About two hours later, the shootings began at a retreat for ruling Labour Party's youth-wing, according to a police official. The official spoke on condition of anonymity because that information had not been officially released by Norway's police. The gunman used both automatic weapons and handguns, he said. It was not clear Saturday whether experts had succeeded in disarming a bomb that the official said had been left unexploded.
 
The blast in Oslo, Norway's capital and the city where the Nobel Peace Prize is awarded, left a square covered in twisted metal, shattered glass and documents expelled from surrounding buildings.