A group of Pakistanis and a Syrian were violently attacked by about 20 unknown assailants late Sunday in the German city of Cologne, police said.
With tensions running high over more than 500 reported assaults against women on New Year's Eve in the western city blamed on migrants, police said Monday that the mob attacked six Pakistanis, two of whom had to be hospitalised.
Shortly afterward, a group of five people attacked a 39-year-old Syrian national, injuring him slightly.
Sunday's violence, in the city centre outside the main railways station marked a new escalation since the rash of assaults occurred during year-end celebrations.
Police on Sunday said they had received reports of "groups of people seeking to provoke" and dispatched reinforcements to the area between the station and the city's iconic Gothic cathedral.
Officers checked the identification of about 100 people and two were detained for refusing to obey police orders.
On Saturday, police used tear gas and water cannon to clear a rally of the far-right PEGIDA movement in Cologne, after protesters flung firecrackers and bottles at officers they accused of failing to prevent assaults during New Year's festivities.
Police said late Sunday that more than a week on from New Year's Eve, some 516 complaints had now been lodged, including 40 percent that are related to sexual assault.
Witnesses described terrifying scenes of hundreds of women running a gauntlet of groping hands, lewd insults and robberies in the mob violence.
The scale of the Cologne assaults has shocked Germany and put a spotlight on the 1.1 million asylum seekers who arrived in the country last year.