BERLIN -- Police say a group of Pakistanis and a Syrian have been attacked in Cologne amid tensions over New Year's Eve assaults in the city that have been blamed largely on foreigners.

They say six Pakistani nationals were attacked Sunday by a group of around 20 people and two of them were briefly admitted to a hospital. Also on Sunday evening, a Syrian man was attacked by five people. He was injured but didn't need treatment.

Police say they are still investigating whether the attacks were racially motivated and whether there was any link to the New Year assaults. Those assaults have stoked tensions over Germany's open-door policy in the refugee crisis and prompted politicians to call for tougher laws against migrants who commit crimes.

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Germany's justice minister said Sunday that authorities need to quickly determine whether the string of New Year's Eve assaults and robberies in Cologne could be linked to similar offenses in other cities.

A regional official confirmed Monday that the majority of the still-unidentifed suspects in the New Year's Eve attacks were believed to be immigrants.

"Witness accounts and the report by the (local) police as well as findings by the federal police indicate that nearly all the people who committed these crimes were of foreign origin," Ralf Jaeger, North Rhine-Westphalia state's interior minister said, according to French news agency AFP.

Police said 121 women in Cologne had filed criminal complaints for robbery and sexual assault -- including two allegations of rape. They said the attackers were among a group of some 1,000 men described as being of "Arab or North African origin" who gathered in front of the Cologne's main train station and gothic cathedral that night, some of whom broke off into small groups that groped and robbed women.

Heiko Maas told Bild newspaper Sunday that if a group came together to commit such offenses, "no one can tell me that this was not coordinated or prepared."

Hamburg saw similar attacks on a smaller scale, and police in other European nations reported cases of comparable trouble in public places.

Maas says "all connections must be carefully checked."

Women's rights activists, far-right demonstrators and leftwing counter-protesters took to the streets of Cologne on Saturday to voice their opinions in the debate that has followed the assaults.

Amid the heightened public pressure, Chancellor Angela Merkel's party proposed stricter laws regulating asylum-seekers in the country -- some 1.1 million of whom arrived last year.

Police said that around 1,700 protesters from the anti-Islam PEGIDA movement were kept apart from 1,300 counter-demonstrators in simultaneous protests outside the city's main train station.

PEGIDA members held banners with slogans like "RAPEfugees not welcome" and "Integrate barbarity?" while the counter-protesters pushed the message "refugees welcome."