If you checked the blog I referred to, entitled "Police: Yes, there ARE No-Go Zones in Sweden" you would learn that there are essentially lawless areas where the police concedes that they have indeed lost control.
So "segregated" is the right word.
https://en.wikipedia.org/wiki/No-go_area
http://www.theatlantic.com/international/archive/2015/01/par...
http://www.bloomberg.com/news/articles/2015-01-14/debunking-...
The source article from the blog states "In the autumn of 2014 reported the National Police for 55 neighborhoods in 22 cities around the country where "local criminal networks is considered to have a negative impact on the local community." It's about neighborhoods that are characterized by "open drug sales, criminal dealings that manifests itself in serious violence in a public place, various forms of extortion and unlawful influence and acting out grievances against society."
The blog post you mention (the author makes no mystery of his ideas), and the source article, seems to take an official report stating that 55 zones have seen a worrying rise in crime and mixing it with anecdotal evidence and unrelated quotes to come to the conclusion that there are 55 "no-go" zones where "swedish law no longer applies", to spin a particular story for their readers.
Mind, I'm not claiming liberal leaning press is any different and, as with everything, the truth probably stands somewhere in between.
I've spent over 30 years of my life in Nordic countries. These stories of embedded lawless mini-Afghanistans ruled by local Sharia tyrants don't reflect any reality I've ever seen.
But there is enough evidence to state that there is segregation.
"Segregation (noun): the action or state of setting someone or something apart from other people or things or being set apart."
Does that mean the United States is hopelessly economically segregated, with permanently unassimilated redneck populations that refuse to join the urban mainstream? If that's an unfair interpretation, why make the same kind of rhetorical leaps about European cities?