Police have carried out extensive raids in four German states on premises linked to suspected far-right extremists.

Thirty properties including flats, offices and commercial premises in the states of Brandenburg, Berlin, Mecklenburg-Vorpommern and Saxony were searched in the operations which began at dawn and continued into Wednesday afternoon.

Police said that no arrests had been made. They are expected to release more information in a press conference on Thursday morning.

According to German media, the focus of the police’s interests is Inferno Cottbus ’99, an extremist group affiliated with the football club Energie Cottbus that has been under investigation since April 2018.

The raids were requested by the main court in the city of Cottbus, which is investigating the group. Inferno Cottbus ’99 is suspected of involvement in criminal activities including robberies, violence, tax evasion and advertising Nazi symbolism, which is a crime in Germany.

Inferno Cottbus has also been accused of organising riots in the eastern city of Chemnitz last summer, sparked by the murder of a local German-Cuban man. According to the group itself, it broke up in May 2017. But observers of the far-right scene say the disbandment happened on paper only.

Cottbus, a city in the state of Brandenburg, has long been seen as a hotbed of rightwing extremism. The state’s office for the protection of the constitution warned that it had become “toxic”.

According to the Berlin newspaper Der Tagesspiegel, police have identified 20 key suspects. As well as being members of Inferno Cottbus, the suspects are also drawn from martial arts groups, security companies, neo-Nazi outfits, and the “rocker” scene.

Jan Gloßmann, a spokesman for the city of Cottbus, said it was struggling to contain its far-right groups. “We have problems with rightwing extremism and its structures,” he told media on Wednesday.

An estimated 400 people are believed to make up the far-right scene in the city and surrounding areas. Their economic activities include running tattoo parlours, security companies, and far-right music labels as well as selling fashion clothing favoured by the far-right.

Meanwhile, figures from Germany’s ruling Christian Democratic party have called for an MP for the rightwing AfD party to step down after reports that he was working under the influence of the Kremlin.

Media reports alleged that Markus Frohnmaier has been closely working with the Russian government and that the Kremlin has been influencing his political decision-making.

According to the reports, the decision to help Frohnmeier and in return receive favours from him came from the Russian president, Vladimir Putin, who is alleged to have intervened just months before the federal elections in the autumn of 2017. Frohnmeier has denied the allegations.