I've often been harassed during my service as a firefighter. It's never been by immigrants or else, but by "the elders of the village" and people alike who could not accept that a road was blocked or we did not want them to run around the place where we were currently working.
Multiple times a year Danish and Swedish media report that paramedics and firefighters are attacked by immigrants or descendents of immigrants in certain areas.
It's not because they are immigrants, Muslims or have brown skins. Something else is going on, but no one cares to find out what that might be, because it might cost money to fix the issue. Blaming peoples origin or beliefs is much easier than fixing a real problem and heaven forbid you where to do something that made the life of immigrants better, people might not vote for you again.