On a recent Sunday, 300 men and women dressed mostly in black met under a radiant blue sky in central Dortmund - the sun reflecting off of some of the participants' shaved heads. Hooligans Against Salafists, abbreviated HoGeSa in German, is the name this group has given itself after coming together by way of social networks.

The meet-up in Dortmund was intended to be a chance for people "to get to know one another" and "have exchanges among each other," according to a video the group put online. "We are Germany," shouts one speaker in the video named Kalle. He's interrupted by clapping and whistling in support before he can manage to get the second sentence out: "We are not right-wing radicals."

Various photos posted online by the group show bulging muscles and many tattoos. Some of the symbols used will be well-known to German intelligence authorities because they suggest affiliation with the far right.

The display in Dortmund was remarkable primarily for peacefully bringing together otherwise sworn enemies drawn from various soccer fan clubs. Neo-Nazi politician and activist Siegfried Borchardt, who also goes by the name SS-Siggi, is believed to have helped bring about the collaboration among the groups, and he was on hand in Dortmund. The 60-year-old founded the soccer fan club Borussenfront in the 80s, which came to notoriety for its violent acts and proximity to the right-wing scene.

Early this year, Borchardt is also said to have invited his old friends - members of various hooligan groups - to a party to discuss current developments in Germany's football fan scene. They're bothered by one development above all: the growing number of left-wing ultras who oppose the political stance of Borchardt and his allies.

Using the law, not crowbars

"They decided to put an end to that in order to revive old values in the stadiums," says German sociologist Gunter A. Pilz, who researches soccer fan culture. He says they see those values as being manliness, toughness and assertiveness. Seventeen hooligan groups, Pilz says, reached the agreement along with organized neo-Nazis, forming a coalition of around 300 people.

Who exactly heads up the group Hooligans Against Salafists remains unclear. At the event in Dortmund, Dominik Roeseler of the right-wing extremist party Pro NRW acted as a spokesman for the group. He was removed from the role for a HoGeSa demonstration planned for Sunday, but the new group's political leanings still seem apparent from its members' social media posts. Recently, the far right band Kategorie C - a fixture within the soccer hooligan scene - dedicated a song to the Hooligans Against Salafists.

On Twitter, users tweeting under the #hogesa tag have written, "This movement must never rest until we are finally in charge of our own country again." One woman wrote, "Germany is finally waking up," while another tweet included a German flag bearing the words, "We don't want a theocracy."

Rainer Wendt, chair of the German Police Union, says the hooligan groups and the right-wing scene more generally are merely exploiting the topic of Salafism in Germany in order to mobilize their sympathizers and attract new supporters. Wendt adds that such groups' frequent assertion that the German state is failing in its fight against Islamists is "nonsense," saying, "What these people don't accept is that we're using legal means to address the matter rather than crowbars."

Low tolerance

Pro NRW's demonstration on Sunday afternoon in Cologne will be monitored by domestic intelligence authorities. More than 5,000 people have registered their participation on Facebook, claiming to travel in from around Europe and organizing car shares to do so. Local police are alarmed given the potential for violence among a number of the groups expected to be on hand. Experts have been working to compile information on who and what to expect at the event.

"The law will be on hand in full force, but with appropriate restraint," said the German Police Union's Rainer Wendt. Acts of violence and the shouting of radical right-wing slogans are not to be allowed, and Wendt says that officers on site will have a low threshold when it comes to intervening.