Riot police in Hamburg have fired water cannon and used pepper spray against people protesting the G20 summit who reportedly threw bottles and other projectiles.
A protest dubbed "G20: Welcome to Hell" had been taking place in the German city with thousands of people taking part ahead of the summit of world leaders.
The BBC reported that 76 police officers were injured with three officers being taken to hospital. There were also reports of injuries among protesters.
Protesters stayed on the streets despite organisers cancelling the march where the first clashes took place and clashes spread to other parts of the city.
Businesses were damaged, cars set alight and makeshift barriers set up by the protesters.
German police had said that 100,000 people were expected in the city over the course of the summit, with 20,000 officers patrolling the Hamburg streets.
Protests had begun near the city's fish market before setting off on a march.
Police told the Associated Press that they had asked a handcore group of anti-capitalists to remove their masks but they had refused. Violence then broke out when police tried to separate them from other protesters.
Pictures from the demonstrations showed water cannon and pepper spray being used against protesters by riot police.
Protesters reportedly attacked a police vehicle, smashing its window with bricks.
Overnight in Hamburg 10 cars were set on fire at a Porsche dealership around 4am on Thursday (6 July) police said they were unsure whether it was connected to G20 protesters but were investigating the incident.
By 9pm local time on Thursday, police said that organisers had ended the march after clashes broke out early on - along with the projectiles, police also said that protesters started fires in the streets.