The chief of police in Cologne has been temporarily suspended over police handling of multiple sexual assaults in the city on New Year's Eve.

Around 100 women reported being sexually assaulted in the city's main square by up to 1000 men, said to be North African in appearance.

Witnesses reported being unable to find police, with some saying they were understaffed.

Wolfgang Albers faced mounting calls for his resignation for his handling of the affair.

Police say they've identified 31 suspects, 18 of whom are asylum seekers.