Apparently, incidents like this happened twice at the main Stockholm youth festival, both 2014 and 2015. But the police hushed it down and withheld information about the frequency of sexual assault on young girls from immigrant gangs due to fears of helping the Sweden Democrats.
It sounds completely insane but since it's reported by our main newspaper which is additionally running a generally very pro-immigration agenda and they're citing highlevel police officials on the record with this information I don't know how it couldn't be true.
Whoever thought up this strategy to deal with the Sweden Democrats was truly idiotic.
If you're an ideologue that genuinely believes that these stories getting out would lead to a backlash against minorities, this being one of the outcomes is completely unsurprising. Frankly, it's inevitable. This is the danger of identity politics. It gets in the way of being able to appropriately identify and solve issues because you value a superficial attribute of a group above the truth.