Police in Cologne detained hundreds of men "of North African appearance" in a New Year’s Eve operation to prevent a repeat of the mass sex attacks in the German city a year ago.

Security forces were taking no chances after they were criticised last year for failing to stop hundreds of robberies and sexual assaults around the city’s main station that were blamed mostly on men of North African and Arab origin.

The local police force tweeted in German, English, French, and Arabic at around midnight on New Year’s Eve that they had screened “hundreds of Nafris”, a colloquial German term for North Africans, at the train station.