Youths have thrown rocks and other missiles at police for a second night running in a suburb of Stockhom.
Around 100 of them came out on the streets and targeted officers and their cars.
The unrest was in Husby, a low income neighbourhood, home mainly to first or second generation immigrants where around a third of school children leave education with low grades.
Ten cars were set ablaze and one fireman was injured when he was hit by a rock.
The police eventually made six arrests.
“They light a fire somewhere and the fire service goes to the scene of the fire. The police have to escort the fire engines and the stone throwing starts again, “ said police spokeswoman Diana Sundin.It is not clear what started the riots in a country which has always been proud of its diverse population and welcoming imigartion policies. However this year the government has indicated it is considering introducing quotas.