Police in Cologne have detained hundreds of men "seemingly of African descent" as part of operations to prevent a repeat of attacks in the German city a year ago.
Police chiefs said the men were detained at two main railway stations so officers could question them and check their identities.
Authorities deployed more than 1,500 officers across Cologne for new year celebrations in response to criticism that they failed to stop hundreds of robberies and sexual assaults last year, blamed largely on men of North African origin.
Some revellers this year complained on Twitter that police appeared to be detaining people based on their appearance.
By early Sunday police had received reports of two women being sexually assaulted in the city. One man was arrested.