German police are hunting for a group of up to a 1,000 men 'of Arab and North African origin' who are accused of sexually assaulting numerous women and causing trouble at Cologne's main station.

Police described the series of sexual assaults against women in Cologne on New Year's Eve as 'a completely new dimension of crime.'

Officers received numerous complaints from women who said they had been assaulted around Cologne's main train station next to the western German city's famous cathedral on the night from Thursday to Friday.

Fireworks are thrown into the crowd outside Cologne's main station, prompting members of the public to flee

German police are hunting for a group of up to a 1,000 men 'of Arab and North African origin' who who have sexually assaulted numerous women and caused trouble at Cologne's main station

The group of men reportedly also robbed their victims and threw fireworks at a crowd of people, according to Breitbart.

Cologne police chief Wolfgang Albers said witnesses described the assaults as coming from a group of up to 1,000 men whose appearance indicated they were of 'Arab or North African origin.'

Some 60 criminal complaints have so far been filed, including one allegation of rape.

German news agency dpa quoted Albers telling reporters on Monday that it was 'an intolerable situation that such crimes are committed in the middle of the city.'

Another firework is let off as a group of men watch on laughing

One of the victims, named only as 'Katja L', gave a harrowing testimony of her ordeal.

'When we came out of the station, we were very surprised by the group that met us there'. She said the group was 'exclusively young foreign men,' she told Der Express.

'We then walked through this group of men. There was an alley through [the men] which we walked through.'

She described the moment she 'felt a hand on my buttocks, then on my breasts, in the end'.

'I was groped everywhere. It was a nightmare. Although we shouted and beat them, the guys did not stop. I was desperate and think I was touched around 100 times in the 200 meters,' she said.

'Fortunately I wore a jacket and trousers. A skirt would probably have been torn away from me'.