
Violent scenes continued into the night at the G20 summit in Hamburg as hardcore anti-capitalist protesters set fires after earlier being hit with water cannons and pepper spray by German riot police.

Dramatic photos showed helmeted officers battling to keep order after 100,000 protesters poured into the city for their 'Welcome To Hell' protest against the meeting of world leaders.

Police say they repeatedly asked a group of demonstrators to remove their masks and hoods but instead officers were hit with bottles and bricks - breaking the window of a riot van.

The violence broke out near the start of the demonstration at a riverside plaza used for Hamburg's weekly fish market.

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A demonstrator stands in the water jet from police water cannon in front of the Rote Flora left-wing centre

A demonstrator shouts to the police during the 'Welcome to Hell' anti-G20 march as officers deal with hundreds of protestors

A demonstrator stands in the water jet from police water cannon in front of the Rote Flora left-wing centre after the 'Welcome to Hell' protest march

A demonstrator stands in the water jet from police water cannon in front of the Rote Flora left-wing centre after the 'Welcome to Hell' protest march

Police stand together as they deal with protestors as the members of the G20 group arrive in Hamburg for talks

More than 100,000 protesters were expected on the streets of Hamburg to protest against the meeting of world leaders. Pictured: Fires burn as riot police and protesters continue to clash

Pictured: Protesters erect burning barricades in front of the Rote Flora left-wing centre after the 'Welcome to Hell' protest march

Organizers quickly called an end to the march after the violence broke out but skirmishes continued into the night. Pictured: Riot police patrol the streets of Hamburg

Pictured: A man throws his hands in the air as he stands in front of burning bins after the 'Welcome to Hell' rally in Hamburg

Pictured: German police deploying a water cannon during a protest against the G20 summit in Hamburg

Pictured: A protester covered in blood is taken away by police during the 'Welcome to Hell' demonstration in Hamburg

Pictured: An injured protester sticks up his finger as paramedics carry him away from the violence in Hamburg

Pictured: A protester stands in front of a police riot van and officers as a water cannon is fired towards him

Pictured: A woman is helped up from the pavement as protesters clash with riot police in Hamburg

Pictured: A man is detained by riot police during clashes between protesters and officers in Hamburg

Pictured: A policeman and a protester tussle on the ground as another officer stands by with a spray can

Pictured: Firemen extinguish a car that was set alight during demonstrations ahead of the G20 summit

The blaze is put out by the firemen (pictured), who are accompanied by police in Hamburg

Pictured: A riot policeman pushes a protester in the road as a flare burns nearby. In the bottom right, a brick can be seen on the pavement

Pictured: A broken shop window in Hamburg as the protest continues in Hamburg

Pictured: A car burns during a protest against the upcoming G20 summit in Hamburg

Pictured: A pizza delivery man encounters unusual traffic as he does his rounds in Hamburg

Protesters jump as they are sprayed by a water cannon during the 'Welcome to Hell' demonstration in Hamburg

Pictured: One woman laughed after being drenched by the riot van's water cannon

Police are already investigating whether an overnight fire at a luxury Porsche car dealership in Hamburg was an arson attack linked to the summit

Pictured: Police firing pepper spray into the crowd of protesters in an attempt to disperse participants of the 'Welcome to Hell' demonstration at the Fish Market

Pictured: German riot police confront protesters during the demonstrations at the G20 summit

Pictured: Pepper spray being fired into crowds of protesters in Hamburg. They can be seen climbing over the wall to the left

Pictured: A woman looks at a man's eye after he was allegedly punched by a policeman during the 'Welcome to Hell' protest

Protesters (pictured) stand in front of a riot van as it sprays its water cannon in front of them

Pictured: Riot police march through the streets of Hamburg as G20 protesters demonstrate

Pictured: Police hold a man on the ground as he is arrested during the protest march in Hamburg

Pictured: A can is thrown as riot police use water cannon during the 'Welcome to Hell' rally against the G20 summit in Hamburg

Pictured: Two people stand in front of an armoured police vehicle with their hands up

A protester (pictured) runs in front of policemen as crowds are dispersed during the demonstration in Hamburg

Pictured: Protesters using smoke bombs during the demonstrations during in northern Germany

Up to 20,000 police officers were on duty to watch over the main demonstration, organised by the alliance of anti-capitalist groups.

Police are already investigating whether an overnight fire which burned down a luxury Porsche car dealership in Hamburg was an arson attack linked to the summit.

Demonstrators gathered at a riverside plaza used for Hamburg's weekly fish market before setting off on a march through the city.

Organizers quickly called an end to the march after the violence broke out, police said. But skirmishes continued, with police advancing down the street with two water cannons while being pelted with bottles by a group of black-clad people.

Pictured: Protesters clash with riot police at the Fish Market in Hamburg

Pictured: German riot police running towards protesters during the demonstration in Hamburg

Pictured: Several armoured police vans spray protesters with water cannons. Police using loudspeakers were also calling on about 1,000 demonstrators to remove masks

Pictured: A protester gestures defiantly towards a police riot van as it sprays him with water

Pictured: A group of protesters is broken off from the main demonstration and surrounded by German riot police in Hamburg

Pictured: Riot police with shields and helmets escort the 'Welcome to Hell' rally in Hamburg as leaders from the world's richest economies descend on the city for talks

Pictured: Onlookers take photographs (left) as the riot vans spray water into the crowd of protesters

Pictured: A riot van firing its water cannon at protesters on the eve of the G20 summit in Hamburg

Pictured: Riot police spray protesters with water cannons as smoke from a flare rises in the streets of Hamburg

Protesters marching during the 'Welcome to Hell' demonstration near the Fish Market ahead of the G20 summit in Hamburg

Pictured: A man puts his hands in the air as riot police move in during the 'Welcome to Hell' rally against the G20 summit in Hamburg

Pictured: Demonstrators wait for the beginning of a protest titled 'Welcome to hell' against the G20 summit in Hamburg

Tens of thousands of anti-capitalist protesters are gathering in Hamburg ahead of US President Donald Trump and other world leaders' arrival for the G20 summit

A giant inflatable 'Black Block' is carried during the 'Welcome to Hell' rally against the G20 summit in Hamburg

Pictured: Demonstrators shout and cheer as they listen to speeches in Hamburg

Protesters wearing black hooded coats and sunglasses hold up a 'Welcome to Hell' banner as they march through Hamburg

Pictured: Protesters covering their faces and wearing black clothes demonstrate against the G20 summit

Pictured: Protesters listening to live music during the rally as leaders from the world's biggest economies come to Germany

Police and hooded protesters meet in Hamburg as G20 leaders arrive in the city for the summit

Pictured: A policeman with a scoped rifle outside the Hotel Atlantic before the beginning of bilateral talks with Chancellor Merkel ahead of the G20 summit in Hamburg

A nearby building was plastered with the slogan 'Borderless solidarity instead of nationalism: attack the G-20.' A small group on the roof set off fireworks.

Police said windows at a furniture store and a bank were damaged. There was no immediate word on a number of arrests or injuries.

Protesters say the G20 has failed to solve many of the issues threatening world peace, including climate change, worsening inequality and violent conflicts.

The event poses a challenge for those tasked with securing the summit of leaders from the world's 20 biggest economies, hosted by Chancellor Angela Merkel.

Pictured: A man in a wheel chair makes his way past riot police during the 'Welcome to Hell' rally against the G20 summit

Pictured: Riot police stand next to protesters, one of whom is brandishing a 'capitalism kills' placard

German police are well prepared for the 'Welcome to Hell' rally. Pictured: Officers guard the road to the guesthouse of the Senate of Hamburg

Pictured: Police march in Hamburg with riot shields and helmets as they prepare for the G20 protest

Pictured: Huge crowds gather by the cranes in Hamburg as leaders from around the world arrive in the city for the G20 summit

As many as 100,000 protesters from across Europe are pouring into the port city for a demonstration dubbed 'Welcome To Hell'

German police fear as many as 8,000 of more than 100,000 protesters amassing in Hamburg are ready to commit violence

Demonstrators gather with anti-G20 banners associating the group of nations with a 'war' on terror, the climate and the poor, adding: 'Not in my name'

Protesters say the G20 has failed to solve many of the issues threatening world peace, including climate change, worsening inequality and violent conflicts. Pictured: A demonstrator raises her hands in the air as music plays during the rally

She faces a monumental talks on navigating through divisive issues including trade and climate change.

Merkel will meet Turkish president Tayyip Erdogan and has already greeted Donald Trump, who today called on NATO allies to spend more on defence and claimed he would 'confront' North Korea.

The German government says Chancellor Angela Merkel and President Donald Trump have discussed issues including North Korea, the situation in the Middle East and the conflict in eastern Ukraine.

A brief government statement gave no further details of the discussion, which lasted a little over an hour, other than to say they discussed 'some issues on the G20 agenda.' It said Secretary of State Rex Tillerson and German Foreign Minister Sigmar Gabriel also participated.

Trump will also have his first session with Russian President Vladimir Putin since he called Russia's behaviour 'destabilising' - a description the Kremlin rejected.

The event poses a challenge for those tasked with securing the summit of leaders from the world's 20 biggest economies, hosted by Chancellor Angela Merkel

At the summit, shrouded by massive protests, Merkel faces a monumental talks on navigating through divisive issues including trade and climate change

Protesters say the G20 has failed to solve many of the issues threatening world peace, including climate change, worsening inequality and violent conflicts

A protester wearing a Donald Trump mask joins in a demonstration ahead of Friday and Saturday's G20 summit

Tens of thousands were expected to gather at the fish market in the borough of St Pauli, known for its red light district, at 2pm - around the same time as Trump's Air Force One jet is due to land in Hamburg. Pictured: A protester holds a flare in central Hamburg

Riot police prepare for G20 protests to begin in central Hamburg, Germany, ahead of the start of the 2017 Summit

Merkel is set to meet leaders including Turkish leader Tayyip Erdogan and Trump, who today called on NATO allies to spend more on defence

Trump will also have his first session with Russian President Vladimir Putin since he called Russia's behaviour 'destabilising'

Prostestors dress up like Zombies in a performance called '1000 Gestalten', prior the upcoming G20 summit

The two-hour show featuring hundreds of actors took was an appeal for more humanity and self-responsibility ahead of the upcoming G20 summit

Merkel, who is running for a fourth term in a September election, stressed today that she was committed to an open international trading system, despite fears of US protectionism under Trump.

'We are united in our will to strengthen multilateral relations at the G20 summit... We need an open society, especially open trade flows,' she said in Berlin.

Several small demonstrations in Hamburg this week have passed off relatively peacefully. On Wednesday more than 7,000 mainly young and beer-drinking revelers staged a march waving placards denouncing capitalism and G20 leaders.

But a fire overnight at a luxury Porsche car dealership in the north of the city that damaged eight vehicles could be a foretaste of what's to come. Police said they were investigating whether it was an arson attack linked to the summit.

Locals are unhappy with Merkel's decision to hold the summit in the centre of Germany's second-largest city to show healthy democracies could tolerate protests, as they are worried about property damage by leftist militants.

After Hamburg authorities curbed camping by protesters, the St Pauli football club offered 200 sleeping places in their stadium as 'a clear signal for human rights, freedom of expression and the right to demonstrate'.

Police said they were investigating whether a fire at a Porsche dealership in Hamburg was an arson attack linked to the summit

Police are seen at a Porsche dealership where a number of cars burnt down overnight ahead of the G20 summit in Hamburg

Pictured: US president Donald Trump arrives in a helicopter for the G20 meeting in Hamburg

The handshake: US president Donald Trump meets with German chancellor Angela Merkel on the eve of the summit

Several small demonstrations in Hamburg this week have passed off relatively peacefully ahead of the summit. Pictured: Canadian Prime Minister Justin Trudeau arriving with his wife Sophie Gregoire and son Hadrien

Locals are unhappy with Merkel's (right, with Singaporean Prime Minister Lee Hsien Loong) decision to hold the summit in the centre of Germany's second-largest city

President of Argentina, Mauricio Macri and First Lady of Argentina, Juliana Awada, arrive at the Hamburg International Airport ahead of the G20 summit in Hamburg

Mayor of Hamburg Olaf Scholz welcomes South Africa's President Jacob Zuma as he arrives for the G20 leaders summit in Hamburg

About 12,000 gathered at the fish market in the borough of St Pauli, known for its red light district.

They will later march north to the heavily secured summit venue.

'It's ridiculous that police say some of us are violent when starting tomorrow the leaders of the world's largest weapons-exporting and importing nations will be arriving in our city,' said Stefan Hubert, a 32-year-old graphic designer.

Holding a placard reading, 'Make love great again!', he added: 'This summit is a waste of money that could be better spent on deploying more boats to stop migrants fleeing war and hunger from drowning in the Mediterranean.'

Turkish-German protester Fatima Cicek said she and her two sisters wanted to make the point that the G20 is undemocratic as it is a forum where a handful of leaders make decisions that could impact the whole world.

But her main issue is with Trump. 'He is the most disruptive and egotistical leader at the summit,' the veiled 38-year-old social worker said.

Turkish-German protester Fatima Cicek said her main issue was with Trump who she described as 'the most disruptive and egotistical leader at the summit'

Merkel has stressed she is committed to an open international trading system, despite fears of US protectionism under Trump (pictured in Poland with wife Melania, Polish President Andrzej Duda and his wife Agata Kornhauser-Duda)

Also present in Hamburg are singers Demi Lovato, left, and Ellie Goulding, right, who are playing at the Global Citizen Festival concert on the eve of the G20 summit

Chris Martin from Coldplay performs on stage during the Global Citizen Festival G20 benefit concert at the Barclaycard Arena in Hamburg

There is irony in the protesters' dislike of Trump. The US president and anti-capitalist activists have something in common: distrust of globalisation.

Yet Trump was in Hamburg to push for trade rules that benefit America, including steelmakers facing tough competition from China, while the protesters were demanding more rights for the poor regardless of where they live.

'Trump is here to promote his own interests and those of the richest people in America,' said Cicek. 'We are demanding more rights for the millions of people in Africa who have no roof over their heads.'