German Chancellor Angela Merkel has welcomed representatives of the 19 countries and the EU to Hamburg. Here she greets Saudi Minister of State Ibrahim Abdulaziz al-Assaf.
Reuters
Russian President Vladimir Putin is there. He is having his first meeting with US President Donald Trump on the summit's sidelines.
AFP
Mr Trump may find himself isolated as other leaders line up to support the Paris Agreement on climate change which he abandoned last month.
Reuters
Canadian Prime Minister Justin Trudeau appealed to Mr Trump to play the lead role in tackling climate change.
EPA
European Commission Jean-Claude Juncker warned the US against imposing punitive tariffs on European steel imports.
AFP
The gathering of the world's most powerful leaders has drawn massive protests in Hamburg. Demonstrators have been trying to "reclaim" the secure area, or Red Zone, which police set up to protect the summit venue.
Reuters
Attempts to block streets with sit-down protests were broken up by riot police on Friday.
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Smoke hung over the city on Friday morning as rioters set cars alight.
EPA
Broken shop windows could be seen.
Fuoco Savinelli
When one young woman got on top of a police armoured car, officers used pepper spray to try to force her off.
Reuters
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Fuoco Savinelli 
Fuoco Savinelli 
EPA