HAMBURG â German security forces clad in riot gear clashed with protesters on the eve of the Group of 20 summit here, using water cannons and pepper spray to disperse a group with anarchist sympathies that had refused to stand down.
The skirmish followed an hour-long standoff on a street that runs alongside Hamburgâs downtown harbor. Thousands of protesters were gathered, and some began lobbing glass bottles and other objects as police rushed a group of âblack blocâ activists huddled in the middle of the street. They were dressed in dark clothes with their faces concealed and carried signs condemning the state and promising, âWelcome to hell.â
Police vehicles rolled toward the protesters, as loud blasts went off, apparently from pyrotechnics set off by protesters. The Hamburg police said at least one of its officials, a spokesman,was injured, and medics could be seen treating injuries on the sidelines of the demonstration.
The street marches and rallies planned for the summit â like at past G-2 gatherings â cover a range of issues including calls for environmental protections, denunciations of ethnic nationalism and opposition to free trade.
But the Hamburg protests have gained added momentum as a stand against President Trump and his brand of âAmerica Firstâ populism. An estimated 100,000 protesters were expected to converge on the old merchant city during the G-20 summit, which begins Friday.
After gathering at the riverside plaza Thursday, protesters began marching through the city. Police called on demonstrators to remove masks, and some clashes were reported, with protesters tossing bottles toward police. Police responded by spraying protesters with water cannons as people recorded the scene on their cellphones.
Video footage showed masked protesters blocking streets with building materials from a construction site and setting small fires. Elsewhere, rows of helmeted riot police backed by water cannons and armored vehicles faced off against demonstrators chanting anti-capitalist slogans.
Authorities mounted the largest police operation in the cityâs history. At least 20,000 officers were being deployed at about 30 registered demonstrations. Forty-five water cannons were on hand to disperse crowds. Some wereÂ used Tuesday evening to clear the streets of early protesters.
Before Thursdayâs protests began, officials had raised fears that they could turn violent. But the gathering at first resembled an open-air concert with bands from all over the world performing. People shared food and art materials for posters, as police formed an enormous cordon.
Moored a short distance away was a ship with a message plastered on its flank â âKeep global trade openâ â at odds with the signs carried by protesters.
The protests draw on a tradition of left-wing activism in Germanyâs second-largest city and the birthplace of its chancellor, Angela Merkel. She is hosting a roster of foreign leaders â including divisive figures such as Trump, Russiaâs Vladimir Putin and Turkeyâs ReÃ§ep Tayyip Erdogan â at a downtown conference center and the lofty Elbphilharmonie concert hall, a crown jewel of the city.
A few miles away is the nerve center of left-wing German radicalism, Rote Flora, a former theater where activists have squatted for nearly three decades. Its members were some of those planning the anti-capitalist protest, which they dubbed âWelcome to Hell.â
Security officialsÂ say the demonstration could draw as many as 8,000 members of the militant left, from Germany and beyond. Among its participants wereÂ âblack blocâ demonstrators with anarchist sympathies who wear dark clothes and cover their faces. Authorities said their concerns mounted following the discovery of materials used to prepareÂ molotov cocktails, along with knives, slingshots and baseball bats. Â
A spokesman for Rote Flora, Andreas Blechschmidt, who registered the demonstration, said his hope is for a peaceful protest. But he promised self-defense âif the police attack us,â saying,Â âViolence can be a productive form of protest.â
A no-fly zone was in place over portions of the city.Â
âNo demonstrator can decide whether or where heads of state and government meet in Germany on the chancellor’s invitation,â said Thomas de Maiziere, the German interior minister.Â
At stake are questions about security, free expression and democratic assembly â newly relevant alongside a summit that, althoughÂ traditionally devoted to economics, may also showcase different approaches to human rights and the rule of law. Merkel, who is chairing the summit, said she willÂ highlight climate, free trade and the shared obligation toÂ assist refugees.
Her critics say her policies are part of the problem.
âThis week is about Angela Merkelâs austerity policy going global via G-20,â said Jan van Aken, a member of the German Parliament representing the far-left Die Linke party.
He criticized the German government for seeking to stamp out protest, saying its approach was autocratic and would âmakeÂ Erdogan, Putin and Trump feel at home here.â
The government is sensitive to this point.
âThe main issue is that the summit is again, after Brisbane, in a democracy,â said Wolfgang Schmidt, a Hamburg politician involved in summit preparations.
Summits in Turkey and China followed the 2014 meeting in Australia. âYou want to make sure that protest and dissenting views are heard, but you also need to maintain security, and with 42 highly protected heads of state and finance and foreign ministers, itâs a challenge.â
Tensions simmered over the weekend and into the week as police used force to removeÂ activists attempting to stay overnight on public land. The courts have said that camps are a protected form of political protest but that authorities may prohibit certain forms of overnight assembly.
Erdoganâs presence pits Turkish nationalists against Kurds, in a country with the largest Turkish community outside Turkey. The German government has disallowed Erdogan from addressing his supporters at the summit.Â
Yavuz Fersoglu, a spokesman for an umbrella organization of Kurdish groups in Germany, said Kurds are joining hands with anti-globalization groups for a major march on Saturday, which organizers say will draw about 100,000 people.
Trump is a particular flash point.
Planning for protests began before his November victory, but âit became clear after his election that the action would have to be much bigger,â said Emily Laquer, a spokeswomanÂ for Interventionistischen Linken, a radical left-wing group in Germany and Austria.Â
Local businesses were preparing for an unpredictable several days.
Richard Canning, the manager of a bar on a cobblestone street near the philharmonic that he said withstood much of the bombing during the Second World War, planned to close on Friday and Saturday out of concern for the safety of his staff.
He said he was sorry to lose business but happy to see Germany take on the difficult role of hosting international negotiations.
âI think that Germany is seen to be one of the major powers in Europe, and rightly so, because since the Second World War it has been building bridges, so Iâm happy itâs holding itself up to the world,â Canning said.
Stephanie Kirchner contributed to this report.