Officials said on Wednesday they were expecting tens of thousands to protest against the international forum for governments and central bank governors of the world’s 20 major economies.
Police said they have also been tracking down known activists coming in from Scandinavia, Switzerland, Italy and elsewhere.
Hamburg police said it is boosting its units with reinforcements from around the country, and will have 20,000 officers on hand to patrol the city’s streets, skies and waterways when world leaders and 6,500 other delegates start arriving on Thursday.
Germany’s counterterrorist GSG9 force will be assisted by Austria’s counterpart Cobra and specialists from the Netherlands and other countries, Hamburg police chief Ralf Martin Meyer told AP news agency.
They will be be stationed around the city in strategic locations to help protect the summit participants.
In a preview of what’s likely to come, police clashed in Hamburg with hundreds of protesters on Tuesday night, using pepper spray and water cannon to against the crowd. Read more here.