Water cannons were fired at thousands of protesters as they clashed with police in the German city of Hamburg where the G20 summit is set to begin.
Demonstrators carrying banners that read: “welcome to hell” and “Smash G20” were raised as the protest that attracted scores of activists descended in to chaos.
Up to 100,000 protesters were expected to march on the city ahead of the summit as police warned of possible violence, saying they had confiscated a number of homemade weapons.
World leaders including US President Donald Trump were at the same time in Hamburg to discuss disagreements over issues such as climate change and trade.
Footage from the march shows masked black-clad anti-capitalist activists hurling bottles and stones at police wearing riot gear as they clashed ahead of the summit on Thursday.
Riot officers used a high-pressured water cannon to separate the angry group as violence broke out near the start of the demonstration in the city.
Thousands of people took part in the protest against the Group of 20 summit titled "G-20: Welcome to Hell," as police called on the group remove their masks.
Demonstrators gathered at a riverside plaza used for Hamburg's weekly fish market Thursday before setting off on their march.
The German government said its Chancellor Angela Merkel and President Trump had discussed issues including North Korea, the situation in the Middle East and the conflict in eastern Ukraine.
