Police are investigating whether a string of sexual assaults and thefts during New Year celebrations in Cologne is linked to a criminal network in the nearby city of Düsseldorf.
The assaults last week have prompted outrage in Germany and triggered a fresh debate about immigration, after police originally said the perpetrators appeared to be of “Arab or North African origin”.
Police said that about 1,000 men had gathered outside Cologne railway station and that smaller groups had surrounded individual women, harassed them and stolen their belongings.
Thomas de Maizière, the Interior Minister of North Rhine-Westphalia state, where Cologne and Düsseldorf are located, said police had identified three suspects but had not yet arrested anyone.
About 90 people filed criminal complaints. At least one woman said she was raped.
Police said some of the assaults in Cologne appeared similar to incidents that have been reported over the past two years in Düsseldorf, where men have groped women to distract them before stealing their belongings. The two cities are 40 kilometres apart.
Authorities have made plain that the nationality and residency status of the Cologne suspects is still unknown, but the incident has nonetheless fuelled anti-immigration sentiment. The anti-Muslim group Pegida has announced a rally outside Cologne station for Saturday night.
Germany registered nearly 1.1 million people as asylum-seekers last year, according to Interior Ministry figures released on Wednesday.
Mr de Maizière urged caution, saying: “You cannot draw a general suspicion against refugees from the indications that they were perhaps people who looked North African.”