The night before, police arrested seven teenagers for throwing stones at the police, for vandalism, and for setting fire to a school and cars in the area.
Jerzy Sarnecki, a criminologist with Stockholm University, tells news agency TT that the time of year, when schools are on the verge of letting out for the summer, can be a factor in explaining the disturbances.
"School work has a certain disciplinary effect," says Sarnecki. "When students have a few days off and it's getting warmer, they gather outside in big groups. What happens then is a sort of game where they show their friends how tough they are."
However, Sarnecki, goes on to say that a number of social problems contribute to the unrest, such as unemployment among the students' parents, alienation, hostility against the police, and not having anything to do. As for why areas like Tensta, Rinkeby and Rosengård in Malmö are hit by periodic disturbances, he explains, "That's where the modern lower class lives."