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 they 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 Supt. Tero Haapala of the National Bureau of Investigation, who headed the probe.

“Some sort of professional knowledge was necessary” to construct the device,” Haapala said. “There were several kilograms of the explosives.”

He declined to give more details pending completion of the investigation.

Interior Minister Ville Itala said he was relieved the police had found a suspect and that there was no apparent link to any terror organizations.

“The main thing is that the matter has been sorted out,” Itala told reporters. “Life goes on. There is no cause for panic.”

A boy looks at flowers and candles in front of the mall where a bomb exploded in Vantaa, Finland. The blast Friday night killed seven people and injured 59 others. It occurred near the spot where a clown had been inflating balloons for children moments earlier.

As many as 2,000 people were at the three-story Myyrmanni mall when the explosion ripped through the building spreading debris and shards of glass over a wide area, minutes after a clown had entertained children with balloons in the vicinity of the blast.

A 7-year-old child died and nine other children were injured, police said.

The powerful blast shocked a country unaccustomed to such violence, and hundreds of people lined up at Red Cross centers to donate blood after a plea from health officials.

“This is the most serious accident since World War II in (the) Helsinki (region),” said Eero Hirvensalo, a physician at Helsinki University Central Hospital.

The government met in an emergency session, and President Tarja Halonen and Lipponen attended a memorial service Saturday at a church nearby.

The Bishop of Helsinki, Eero Huovinen, who conducted the service said Finland no longer was immune to violence.

“Distress grew when we heard that this was a crime,” Huovinen said, his voice breaking with emotion. “The world, here too, is no longer a haven of safety.”