Revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. Germany is celebrating its traditional carnival with tight security after assaults on women during New Year's Eve celebrations across the country. (Photo by Kai Pfaffenbach/Reuters)





A reveller talks to police during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. After a string of robberies and sexual assaults on New Year's Eve in the city that police say were committed largely by foreigners, German authorities are keen to avoid a repeat of those events during the five-day street party. (Photo by Martin Meissner/AP Photo)





Carnival enthusiasts cheer and celebrate in front of the cathedral in Cologne, Germany, Thursday February 4, 2016. The street carnival has started in Cologne under increased security measures. After a string of robberies and sexual assaults on New Year's Eve in the city that police say were committed largely by foreigners, German authorities are keen to avoid a repeat of those events during the five-day street party. (Photo by Maja Hitij/DPA via AP Photo)





Female carnival revellers walk in front of the main station during “Weiberfastnacht” (Women's Carnival) in Cologne, Germany February 4, 2016. Women's Carnival marks the start of a week of street festivals, the highlight of the event being “Rosenmontag” (Rose Monday), the final day of the yearly carnival season where mass processions are held. (Photo by Wolfgang Rattay/Reuters)





A mobile surveillance camera stands in front of an electronic information sign during “Weiberfastnacht” (Women's Carnival) in Cologne, Germany February 4, 2016. (Photo by Wolfgang Rattay/Reuters)





Police patrol as revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





Cologne Mayor Henriette Reker takes part in the “Weiberfastnacht” (Women's Carnival) celebrations in Cologne, Germany February 4, 2016. (Photo by Wolfgang Rattay/Reuters)





Police patrol as revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. Germany is celebrating its traditional carnival with tight security after assaults on women during New Year's Eve celebrations across the country. (Photo by Kai Pfaffenbach/Reuters)





Revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





A police officer wearing a new so-called “body-cam” laughs with a reveller selling sunglasses during the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





A reveller takes part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





Police patrol as revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





A reveller walks past police during the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





Police patrol as revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





Police patrol as revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. (Photo by Kai Pfaffenbach/Reuters)





Revellers walk past an empty bottles of alcohol during the “Weiberfastnacht” (Women's Carnival) celebrations in Cologne, Germany February 4, 2016. (Photo by Wolfgang Rattay/Reuters)





A reveller jokes next to a police officer during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





Police patrols in front of the main station during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





A reveller gets a kiss during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





A female reveller celebrates in front of the cathedral during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





A police helicopter flies near the Cologne cathedral during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





Security checks a reveler costumed as Elvis in front of a pub during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





Female revelers passing a women's security point during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





A reveler dressed as a storm trooper accompanies a woman during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)





Clowns standing in the rain during the start of the street carnival in Cologne, Germany, on Thursday, February 4, 2016. (Photo by Martin Meissner/AP Photo)