German state interior minister Ralf Jaeger has said migrants were almost exclusively responsible for the attacks on women in Cologne on New Year's Eve.
More than 100 women reported being threatened, robbed or molested during the city's celebrations.
The minister's comments come amid reports a group of Pakistanis and a Syrian were violently attacked by about 20 unknown assailants on Sunday in the city.
German police say a group of Pakistanis and a Syrian were violently attacked by about 20 unknown assailants on Sunday in Cologne.
There are raised tensions in the city after an anti-migrant rally followed new year's eve attacks on women.
Police say the mob attacked six Pakistanis, two of whom were hospitalised. Shortly afterward, a group of five people attacked a 39-year-old Syrian national, injuring him slightly.
The German Chancellor wants increased powers to block foreigners from being granted asylum if they have any sort of criminal record.
Around 400 people gathered in Cologne to demonstrate against violence against women following a wave of assaults on New Year's Eve.
Authorities in Cologne are holding crisis talks on Tuesday after a string of sexual assaults by large gangs of men.