Thousands of demonstrators, including anarchist groups and extremist elements, are expected to descend on Hamburg to voice their grievances against world leaders at the two-day G20 summit this week. But residents of Germany’s second most populous city say they are using this unique opportunity to peacefully protest, and that the threat of violence and increased police presence is not a deterrent.

“Protest is being demonised,” says George Letts, a 52-year-old communications consultant from Hamburg. “It is very disturbing to know that some of the worst and most antidemocratic politicians will be coming to my city.” Letts plans to take part in the protest on Saturday, where 100,000 people are expected to join in the “G20 not welcome” march, which promises to be peaceful.

“A lot of people in the city want to show how democracy works as a sign to the Trumps, Erdoğans and Putins of the world. But the hard restrictions by the local politicians and police authorities make it difficult to demonstrate,” he says.

Local residents, who responded to an online callout, say there is a heavy police presence, with helicopter patrols over residential areas and reports of arrests and the use of water cannon. They say the majority of protesters are calm, but the increased police presence is adding tension.

“The police have a mighty difficult job to do, as there are some protesters here just for a fight,” says Jim Maloney, 42, who lives in Altona, a district of Hamburg. “This, as is always the case in larger protests, represents the minority. It would be nice for the police to differentiate,” he says.

Asked why he is taking part in the protest, Maloney says he is proud of his diverse and liberal city, and wants to make a stand against world leaders who, he says, push policies and opinions that curtail openness and tolerance.

“Why is Donald Trump in our city and moreover in our suburb? He stands against everything we hold dear. There are other leaders that deserve scorn but none more than Trump. He represents free trade and business as Hamburg does but fundamentally without the social responsibility and openness that Germans and particularly those in this city hold dear,” he says.

People gather at the Rote Flora, a cultural and political venue that has become a symbol of the radical left, for anti-G20 protest planning before the G20 summit. Photograph: Sean Gallup/Getty Images

Laurel, 47, a speech instructor who lives in Hamburg, says she will be attending the protests as she did at the G20 summit in Toronto. She says there has been an increased police presence even when no protests were taking place, including at a music night she attended on Tuesday which, in part, highlighted the plight of refugees entering Europe.

“I am protesting the presence of riot police and their scaremongering tactics in what have so far been very peaceful demonstrations. I am peacefully protesting the role banks and financial institutions play in influencing governmental policies.

“Profit above everything else affects climate change and freedom of movement – issues Merkel has tabled for the summit,” she says.

Ralf, 49, a coordinator from Hamburg, says he has been forced to work from home due to the increased police presence and disruption in the city. Ralf says he intends to demonstrate on Saturday, to make a stand against the disparity of wealth around the world, climate change, and the rise of nationalism.

He says the police are using unnecessary force and dismantling camps, but the threat of violence will not put him off attending.

“I will be very wary of any type of aggressive behaviour or conflicts and try to avoid it as much as possible. I am definitely for a peaceful protest and wouldn’t do anything that would provoke the police, which is massively present here. The police seem to be nervous and are apparently overcompensating their sense of uneasiness … dismantling authorised camps, using pepper spray and water cannon against so far absolutely peaceful protesters,” he says.

A “G20 not welcome” march on Saturday is expected to attract up to 100,000 members of anti-fascist, feminist and climate activist groups. Photograph: Wolfgang Rattay/Reuters

The majority of residents who responded to the Guardian say they are unhappy with the summit’s location; a residential, and central, part of Hamburg. They say it is causing disruption to the daily lives of residents and curtailing human rights, and the additional security demands are a waste of taxpayers’ money.

“We need to close down shops, restaurants and bars without seeing a single penny for compensation,” says Davina, 26, who lives in the Sternschanze district next to the G20 venue. She says she is protesting not only against the politicians, but also against the location of the summit.

“I’m not a protester, and I could easily go to the countryside but it’s my business. Trump is not welcome here. Neither is Erdoğan or Putin. We are setting a clear sign that their politics and opinions are not welcome.

“But why plant a summit that violates many basic human and social rights for close-by residents right in the neighbourhood of social activists who are known for using violence to protest and to get what they want? It can only end in chaos,” she says.

Davina says the protests have been peaceful so far, but she fears the violence may escalate.

“We have been demonstrating and the vibes were great. People were dancing through the streets. There was loud music everywhere. It was peaceful and there were tens of thousands of protesters. But the closer we get to Saturday, the worse it will get,” she says. “I am officially worried for my friends … we need to prepare ourselves for things to become very messy.”

More protesters are expected over the weekend, with more than 100,000 expected at Saturday’s march. Anna Jones, 44, says she plans to travel from Helsinki to the protests this weekend. She says she is protesting against policies and political decisions that make the world’s population poorer, as well as government-supported wars.

“I couldn’t be more angry with all these [problems], and public demonstrations and acts against police are fundamental.

“These meetings are just propaganda and more waste of public money. There were never any global government resolutions, regulations … only the opposite,” she says. “We have a total lack of common policies which compromises our future generations and the planet.”

If you’re taking part in the G20 protests, we’d like you to tell us why. You can share your thoughts via our online callout here. Or you can email: carmen.fishwick@theguardian.com

*some names have been changed.