That comes mainly from the fact that Algeria, Morocco and few other countries are now on the list of "safe countries to return to" according to Germany, so if people from those countries would try to apply for asylum in Germany now they would be unlikely to get an asylum. But just a while ago that was not true so they could have arrived as refugees before that or they might have immigrated otherwise, some apparently are illegally in Germany.
And in either case, the terms refugee and immigrant are being mixed up on purpose these days. Using crimes committed by foreigners to claim that refugees did them and inciting hate against them, claiming that the refugees don't actually need an asylum (as well as claims that they should have stayed and fought for their country and are cowards by leaving. If you try to ask who they should have been fighting for in a six way civil war the response is usually "the government" or "their own ethnic/religious group..." Because the people who usually make these claims are the kinds of people who would fight for Daesh if they lived in the region and no, this is not an hyperbole.) or even claims that the refugees/immigrants are ALL part of a secret Muslim invasion.
