The source said that the investigation is already under way and that the attackers have yet to be identified.
"At the moment we have yet to confirm that the attack was staged by refugees. However, we have already gotten in touch with one of the witnesses of the incident, who we hope will help us to successfully complete the investigation," the source said.
The remarks came shortly after a video emerged in social networks showing a group of migrant men attacking two pensioners when they kept them from groping a young woman on a subway train in Munich. Specifically, the footage showed a gang of about five men seizing one elderly man by the arms and abusing him verbally.
A second elderly victim can be seen fighting one of the assailants and then being held up by the neck and threatened. The melee allegedly broke out after one of the attackers was rejected by a woman after he had put his hand on her in the train.
Dozens of women were robbed, sexually assaulted, and raped on New Year's Eve in Cologne by groups of aggressive men, mostly of Arab and North African descent.
Earlier this month, the German news network Deutsche Welle reported that sexual attacks like the ones that happened in Cologne on New Year's Eve had also happened elsewhere in Germany. According to a confidential report cited by Deutsche Welle, 27 such incidents were registered in Bavaria, most of them in Nuremberg and Munich. In Bremen, there were 11 reports, in Berlin six and in Baden-Wurttemberg, 25.