LONDON — At first, there was complete silence from officials. As rumors spread on social media, police had nothing to say about allegations of mass sexual assaults and other crimes carried out on New Year's Eve in the German city of Cologne.

It was only days later that officials reported that hundreds of women were victims of assault in Cologne, Hamburg and other German cities.

But numbers that are now emerging are likely to shock a country still coming to terms with what happened in Cologne more than half a year ago. According to a leaked police document, published by Germany's Sueddeutsche Zeitung newspaper and broadcasters NDR and WDR, the previous estimates have to be dramatically revised — upward.