Asylum seekers were among those involved in the violence on New Year's Eve in Cologne, the German interior ministry said on Friday.

Ministry spokesman Tobias Plate told a news conference that federal police had identified 31 people by name who played a role in the violence, 18 of whom were in the process of seeking asylum in Germany.

Plate said the vast majority of the 32 criminal acts documented by federal police on the night were tied to theft and bodily injury. Three were related to sexual assaults, although police had no names tied to these acts.

He said of the 31 people questioned, nine had been Algerian, eight Moroccan, five Iranian, and four Syrian. Two German citizens, an Iraqi, a Serb and a U.S. citizen were also among those seen to have committed crimes during the night.

Meanwhile, Swedish police say at least 15 young women have reported being groped by groups of men on New Year's Eve in the city of Kalmar.

Kalmar police spokesman Johan Bruun on Friday said groups of men encircled women on a crowded square and groped them. He said no one was physically injured but that many of those targeted were terrified.

He said two men, both asylum-seekers, were informed through interpreters that they're suspected of sexual assault and that police are trying to identify other suspects.

Asked about similarities to assaults in Germany, Bruun said "we are aware of what happened in Germany but we are focusing our investigation on what happened in Kalmar."