VANTAA, Finland -- Police searched for a motive Saturday behind a blast in a quiet suburban Helsinki shopping mall that killed seven people, including the suspected bomber, injured 80 others and shocked this normally peaceful nation.
"Nothing like this has happened in Finland before," Prime Minister Paavo Lipponen said of Friday's bombing at a crowded mall in Vantaa, about 10 miles north of the capital, Helsinki.
Police said the male suspect, a Finnish chemistry student with no criminal record, was killed in the blast, but did not say why they thought he set off the bomb, which was packed with shotgun pellets.
Police said they had no evidence to indicate it was an organized terrorist attack. Lipponen said he believed it was an isolated incident with no connections to terrorism.
"We have no motive," said Chief Superintendent Tero Haapala of the National Bureau of Investigation, who headed the investigation.
"Some sort of professional knowledge was necessary" to construct the device," Haapala said. "There were several kilograms (pounds) of the explosives."