24 May 2013 Last updated at 12:07 ET
Sweden reinforcing police in riot-hit Stockholm
The BBC's Steven Evans in Stockholm: "The whole policy of immigration and integration is being questioned"
Reinforcements of specially trained police are being sent to Stockholm after five nights of unprecedented rioting in the capital's suburbs.
Police officers are being sent from the cities of Gothenburg and Malmo, both of which saw rioting in recent years, a spokesman told BBC News.
"They are trained and educated for the police tasks going on in Stockholm," Kjell Lindgren said.
Several schools and scores of cars have been burnt in Stockholm this week.
The nightly riots began on Sunday in the north-western suburb of Husby, a deprived, largely immigrant area. It is believed they were sparked by the death of a man nearly a week before, who was shot by police after he allegedly threatened to kill them with a machete.
The unrest has since spread around the city, with groups of youths stoning police and firefighters summoned to tackle arson attacks.
The rioting has raised questions about the success of the country's attempts to integrate foreign-born residents, who now make up some 15% of the population.
In Husby, more than 80% of the 12,000 or so inhabitants are from an immigrant background, and most are from Turkey, the Middle East and Somalia.
Community activists have accused the police of using racist language during the unrest and prosecutors are investigating complaints. Police have tried to calm the situation by speaking to community leaders, such as in mosques.