Greenpeace demonstrate with a puppet depicting U.S. president Donald Trump, during the G-20 summit in Hamburg, Germany.  Picture: Boris Roessler/dpa via AP
Greenpeace demonstrate with a puppet depicting U.S. president Donald Trump, during the G-20 summit in Hamburg, Germany. Picture: Boris Roessler/dpa via AP
An injured police officer is attended by fellow officers during skirmishes with demonstrators on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
An injured police officer is attended by fellow officers during skirmishes with demonstrators on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
Police use a water cannon to clear a road on the first day of the G-20 summit in Hamburg, northern Germany. The leaders of the group of 20 meet July 7 and 8. Picture: Matthias Schrader/AP
Police use a water cannon to clear a road on the first day of the G-20 summit in Hamburg, northern Germany. The leaders of the group of 20 meet July 7 and 8. Picture: Matthias Schrader/AP
Demonstrators who blocked a street flee from police on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
Demonstrators who blocked a street flee from police on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
The G-20 participants and their spouses pose for a family photo in front of the Elbphilharmonie concert hall on the first day of the G-20 summit in Hamburg. Picture: Markus Schreiber/AP
The G-20 participants and their spouses pose for a family photo in front of the Elbphilharmonie concert hall on the first day of the G-20 summit in Hamburg. Picture: Markus Schreiber/AP
US President Donald Trump, left, and his wife Melania smile prior to a concert on the first day of the G-20 summit in Hamburg, northern Germany. Picture: Markus Schreiber/AP
US President Donald Trump, left, and his wife Melania smile prior to a concert on the first day of the G-20 summit in Hamburg, northern Germany. Picture: Markus Schreiber/AP
German chancellor Angela Merkel  waits to welcome guests at the start of the G-20 summit in Hamburg. Picture: Christian Charisius/dpa via AP
German chancellor Angela Merkel waits to welcome guests at the start of the G-20 summit in Hamburg. Picture: Christian Charisius/dpa via AP
US President Donald Trump, left, is welcomed by German Chancellor Angela Merkel on the first day of the G-20 summit in Hamburg, northern Germany. The leaders of the group of 20 meet July 7 and 8. Picture: Jens Meyer/AP
US President Donald Trump, left, is welcomed by German Chancellor Angela Merkel on the first day of the G-20 summit in Hamburg, northern Germany. The leaders of the group of 20 meet July 7 and 8. Picture: Jens Meyer/AP
President Donald Trump meets with Russian President Vladimir Putin at the G20 Summit. Picture: Evan Vucci/AP
President Donald Trump meets with Russian President Vladimir Putin at the G20 Summit. Picture: Evan Vucci/AP
Russian President Vladimir Putin, left, is welcomed by German Chancellor Angela Merkel on the first day of the G-20 summit in Hamburg. Picture: Michael Sohn/AP
Russian President Vladimir Putin, left, is welcomed by German Chancellor Angela Merkel on the first day of the G-20 summit in Hamburg. Picture: Michael Sohn/AP
Demonstrators turn waste bins on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
Demonstrators turn waste bins on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
People look at a burnt-out car  in Hamburg, Germany, after protests against the G-20 summit. Picture: Axel Heimken/dpa via AP
People look at a burnt-out car in Hamburg, Germany, after protests against the G-20 summit. Picture: Axel Heimken/dpa via AP
A firefighter puts out a fire  during a protest against the upcoming G-20 summit in Hamburg.   Picture: Bodo Marks/dpa via AP
A firefighter puts out a fire during a protest against the upcoming G-20 summit in Hamburg. Picture: Bodo Marks/dpa via AP
Demonstrators turn waste bins on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
Demonstrators turn waste bins on the first day of the G-20 summit in Hamburg. Picture: Matthias Schrader/AP
German Chancellor Angela Merkel, second from left, looks to France's President Emmanuel Macron when posing for a photo prior to a concert on the first day of the G-20 summit in Hamburg. Picture: Markus Schreiber/AP
German Chancellor Angela Merkel, second from left, looks to France's President Emmanuel Macron when posing for a photo prior to a concert on the first day of the G-20 summit in Hamburg. Picture: Markus Schreiber/AP

Hamburg - As international Group of 20 leaders assemble at a landmark philharmonic for dinner and to listen to Beethoven's Ninth Symphony, a massive police presence is keeping protesters outside the Hamburg concert hall at bay.

Six helicopters are hovering in the sky, three large police patrol boats and several smaller ones are guarding the waters around the philharmonic located on a peninsula in the harbor.

Around 200 police officers stood shoulder-to-shoulder on the bridge leading to the concert house, where American conductor Kent Nagano was to lead an orchestra in Beethoven's Nine, the European Union's anthem.

The leaders and their spouses were getting together for a festive dinner afterward.

Police and anti-globalization activists have been clashing in Hamburg for a second day in violent skirmishes across the city.

Associated Press