I am curious, is the rise of violent crime somehow linked with migration from Asia and Africa or it is a completely unrelated issue and most of the criminals come from families who have lived in Sweden for many generations?
It's largely second generation immigrants (yes, mostly from Africa and the Middle East, since that's where most immigration - in the shape of refugees - comes from).
And take it from someone who actually lives in the area (as opposed to HN speculators): YES it has gotten significantly worse over the last five years (having already been bad for decades), and YES 14 year old hitmen with explosives and automatic weapons are now an actual thing, not just a couple of incidents.
The politics of this is so inflamed, which makes it harder to discuss, much less solve the problems. I am not against immigration per se, from any given country. But right now, it is obviously causing major problems that need to be handled with extreme prejudice.