There have been calls for Cologne's Chief of Police to quit after more than 100 women were sexually assaulted and robbed during the city's New Year's Eve celebrations.

German Police initially failed to mention the attacks in their reports on New Year's Day, describing the festivities as "largely peaceful".

A spokesperson said Gilles said police were well prepared on the night, but they were "surprised" by the scale and aggression of the attacks.

It is believed around 1,000 men split into gangs after being dispersed by officers for throwing fireworks.

Meanwhile, the city's mayor Henriette Reker has urged young women to adopt a code of conduct to prevent such attacks in the future.