Riots in Sweden: the true reason?

Riot acts have occurred in Stockholm since May 19th. Groups of youth smashed shop windows, ignited fireworks, and threw stones to firefighters. Destruction in several areas was continuing and over 29 persons have been arrested.

Some media say that these destructive events are a response to the case of an old armed man killed by the police occurred on May 13th.
Megafornen, an association of civil activists in Stockholm, published a comment that the rioters were angry against the cruel acts as usual of the police.

Many media also mention the difficulty of the policy on immigration. The fact that a lot of immigrants live at Husby, where the first riot occurred, made them consider about this matter.

However, according to the Guardian, the reason of the riots is complicated. The main complaint of the violent youths may be unemployment.

The Guardian: Swedish riots rage for fourth night

Today I watched an article described by a Japanese scholar live in Sweden.

Sweden Now: About the riot at a suburb area in Stockholm (in Japanese)

He guesses that the riot was not so organized, and had no intention of political intention. Youths make sometimes tricky behaviors as usual, such as at the end of the year. Their immature activities were escalated for some reasons. And the activists made use of these events for their own propaganda, the author says.

I do not know the truth. But I remember the similar cases occurred in the UK in 2011. The series of riots began after the shooting case of Black man killed by the police. However, it is quite doubtful that members participated in the riots had political intention.

There are some risks to occur destruction. Nevertheless, it is difficult to control, even identify them. Even if a certain event ignited the rioters, it is not certain that the event is the true motivation of the riot act.