Though Merkel has decried the assaults as "repugnant criminal acts that ... Germany will not accept," they provide fodder for those who have opposed her open-door policy and refusal to set a cap on refugee numbers.
Influential Hamburg broadcaster NDR said in an opinion piece posted online Friday that such crimes threaten to push xenophobia toward the "middle of the population" — which could lead to a backlash against refugees.
"And who is to blame mainly?" the editorial asked. "These young, testosterone-driven time bombs with their image of women from the Middle Ages."
Despite the harsh rhetoric, the case is not yet that clear and the investigation is ongoing.
Of 31 suspects temporarily detained for questioning following the New Year's Eve attacks, there were 18 asylum seekers but also two Germans and an American among others, and none were accused of specifically committing sexual assaults.
Cologne police on Saturday said more than 100 detectives are assigned to the case and are investigating 379 criminal complaints filed with them, about 40 percent of which involve allegations of sexual offenses.
"The people in the focus of the criminal investigation are primarily from North African countries," police said. "Most are asylum seekers or people living illegally in Germany. The investigation into if, and how widely, these people were involved in concrete criminal activity on New Year's Eve is ongoing.