Sweden has failed to integrate the vast numbers of immigrants it has taken in over the past two decades, leading to parallel societies and gang violence, Prime Minister Magdalena Andersson said on Thursday, as she launched a series of initiatives to combat organized crime.

Many Swedes were shocked earlier this month after violent riots left more than 100 police injured. The violence erupted after a Swedish-Danish politician burned the Quran at a rally and sought to hold more in several immigrant-dominated neighborhoods.

Andersson blamed criminals and said both Islamism and right-wing extremism had been allowed to fester in Sweden, in unusually frank and self-critical comments.