Hundreds of sex offenses were reported in Cologne, Düsseldorf, Hamburg, Frankfurt and Stuttgart last New Year's Eve, plus incidents of touching and groping while trying to steal phones, purses or bags, according to Germany's Federal Criminal Police Office.

The ugly scenes in Cologne in particular made international headlines, with almost 1,200 criminal complaints made to the police that night and in the following days - including about 500 related to sexual assault. Most of the attacks occurred in the area surrounding the city's Gothic cathedral and the adjacent main train station.

Almost a year later, security measures aimed at preventing mass sex mob attacks and making sure visitors have a safe and enjoyable start to 2017 are in place for a night that traditionally draws huge crowds to the city on the Rhine.

A significantly beefed-up police presence is a key part of the new security concept.

Cologne police wearing reflective vests that make them highly recognizable will be present with 1,500 officers on duty on December 31, city police chief Jürgen Mathies said on Monday at a presentation of the city's security plan for New Year's Eve.

"What happened last year can never happen again," Mathies said.

Ten times as many police officers

With 140 police officers on duty last year, Cologne police were woefully inadequate to the task of dealing with the mass sex assaults.

The designated fireworks-free zone around Cologne Cathedral

This year, an additional 300 federal police officers and about 600 city security officials will patrol the center of Cologne that night, while trained specialists will be ready to help women and girls in cases of harassment, intimidation, assault or rape.

The city is also limiting access to the immediate area around the cathedral. Bags will be searched, while firecrackers and other pyrotechnics will be strictly prohibited in the cordoned-off area.

Surveillance and bright lights

The downtown area is traditionally packed with Cologne residents and visitors on December 31, shooting off fireworks in the shadow of the towering cathedral, or passing by on their way to bars, the train station or to the nearby Hohenzollern Bridge - a popular place to watch the firework displays.

To guarantee safety and avoid "unclear situations," bridges across the river will be blocked at certain times into the early morning hours.

Police chief Mathies and Mayor Reker are confident the right measures are in place for New Year's Eve

Video surveillance cameras will be in place in front of the main train station, the site of many assaults last year. These areas will also be more brightly lit than usual.

And not simply better lit: an internationally renowned light artist has been hired to illuminate the area around the cathedral, the adjacent square and several buildings with bright colors, overlapping shapes and words.

"After last New Year's Eve's shocking assaults, the city has taken appropriate measures," Mayor Henriette Reker told reporters on Monday. "We want people to experience the true Cologne: peaceful, joyful - a city with a sense of community."