A nearly weeklong spate of rioting has spread outside Stockholm, but authorities say police reinforcements sent to the Swedish capital have reduced the violence there.
As many as 25 cars had been burned and a police officer was slightly injured on the sixth straight night of violence in mainly immigrant areas of Stockholm.
Kjell Lindgren, Stockholm police spokesman, said on Saturday that 19 people have been detained in connection with the rioting, but there had been no hurling of rocks against officers as in previous days.
Two cars were torched in Stockholm but the city appeared to have had its calmest night since the trouble began.
However, in Orebro, a town in central Sweden, about 25 masked youths set fire to three cars, a school and tried to torch a police station, police said. An old empty building was set alight in the town of Sodertalje, less than an hour's drive from the capital.
Pupils at a primary school in the Stockholm suburb of Kista - an information-technology hub that is home to the likes of telecoms equipment maker Ericsson and the Swedish office of Microsoft - arrived on Friday to find that the inside of the small red wooden building had been burned out.
"In the short run, the acute thing is to ensure that these neighbourhoods get back to normal everyday life," Erik Ullenhag, Sweden's integration minister, told the Reuters news agency.
"In the long run we need to create positive spirals in these neighbourhoods."
The police said they had called in back-up from the cities of Malmo and Gothenburg.
Fredrik Reinfeldt, Sweden's prime minister, held an emergency meeting on Friday to discuss the crisis.
The bout of destruction was sparked by the fatal police shooting earlier this month of a 69-year man, reported by local media to be a Portuguese immigrant and suspected of wielding a large knife, in the Stockholm suburb of Husby.
The scale of riots pales beside the disturbances seen in London and Paris in recent years and there have been almost no injuries. Much of the capital has gone about business as normal.
But the violence - with more than 100 cars set ablaze this week - has shocked a nation that has long taken pride in its generous social safety net.
Youth unemployment is especially high in neighbourhoods such as the ones where the riots have taken place, home to asylum seekers from Iraq to Somalia, Afghanistan, Syria, Latin America and war-torn countries.
About 15 percent of Sweden's population is foreign-born.
Kicki Haak, head of the small Montessori school that was set alight in Kista on Thursday night, said she did not know if it would be able to reopen. The 94 students will move into improvised classrooms in nearby office buildings on Monday.
There are signs that residents in the affected areas are getting fed up with the violence. Many community leaders, dressed in fluorescent jackets, have taken to the streets to try to calm things down.
Risto Kajanto, brother-in-law of the man who was shot dead, told the Swedish tabloid Aftonbladet he condemned the violence.
"I want to say to all those who are burning cars that it is totally wrong to react that way," he said.
One recent government study showed up to a third of young people aged 16 to 29 in some of the most deprived areas of Sweden's big cities neither study nor have a job.
The gap between rich and poor in Sweden is growing faster than in any other major nation, according to the Organisation for Economic Co-operation and Development, although absolute poverty remains uncommon.