http://www.bbc.com/news/world-europe-35231046
The mayor of Cologne has summoned police for crisis talks after about 80 women reported sexual assaults and muggings by men on New Year's Eve.
The scale of the attacks on women at the city's central railway station has shocked Germany. About 1,000 drunk and aggressive young men were involved.
City police chief Wolfgang Albers called it "a completely new dimension of crime". The men were of Arab or North African appearance, he said.
Women were also targeted in Hamburg.
But the Cologne assaults - near the city's iconic cathedral - were the most serious, German media report. At least one woman was raped, and many were groped.
Most of the crimes reported to police were robberies. A volunteer policewoman was among those sexually molested.
What is particularly disturbing is that the attacks appear to have been organised. Around 1,000 young men arrived in large groups, seemingly with the specific intention of carrying out attacks on women.
Police in Hamburg are now reporting similar incidents on New Year's Eve in the party area of St Pauli. One politician says this is just the tip of the iceberg.
And there are real concerns about what will happen in February when the drunken street-parties of carnival season kick off.