The small German city of Themar became home this weekend to a large neo-Nazi rock concert called “Rock Against Foreign Domination.”

Several thousand fans showed up to the eastern city, the population of which swelled from 3,000 to nearly 6,000. The concert is Germany’s largest neo-Nazi affiliated event, although the number of similar types of events appears to be growing. German media reported last year that in the first half of 2016, Germany had already been host to nearly 100 far-right wing cultural events like this weekend’s concert. During the same time period the year before, only 63 similar events had taken place.

Concert attendees donned t-shirts emblazoned with slogans like “I Love Hitler” and “Hakenkreuz,” the German term for swastika. While it is legal to write the word for the infamous symbol, it is illegal to show, wear, or otherwise publicly present Nazi symbols.