Personally, it wouldn’t surprise me one bit to find out that it was in fact, Muslims themselves who scribbled the symbols…

Islam is very, very compatible with the Nazi ideology. However, vandalizing private/public property is an anathema in a free society predicated to the rule of law, no matter who does it.
Stockholm mosque hit with Nazi graffiti
Unknown vandals spray-painted swastikas on the facade of a central Stockholm mosque on Friday night, mosque officials said.
The Nazi graffiti can be seen scrawled across the front doors of the Södermalm mosque in light blue paint in photos the mosque
posted to Facebook.
The mosque’s imam, Mahmoud Khalfi, said that the vandalism was extensive.
“It was on the entire facade, including the back and along the stairs to the subway,” Khalfi told SVT.
According to the imam, the mosque was targeted by vandals 22 times during 2017. The mosque has been hit with Nazi-specific vandalism twice before, with the
first incident occurring in 2014.
“Yet again, Stockholm Mosque has been vandalised,” the Facebook post read. “Here is what visitors were greeted with this morning.”
More here.