Despite an attempt by right-wing extremists to disrupt the festivities, tens of thousands of people gathered in the eastern German city of Chemnitz on Saturday as it took over the mantle of European Capital of Culture.

Under the motto "C the Unseen," in reference to the city's lesser-known status abroad, Chemnitz is to host more than 200 projects and 1,000 events over the year.

Previously known as Karl Marx City in the former East Germany, Chemnitz today has a population of around 240,000.

At the opening ceremony, German President Frank-Walter Steinmeier encouraged people to explore the fourth-largest city in eastern Germany after Berlin, Leipzig and Dresden.

"If you've never been to Chemnitz before, if you never heard if it, then you've already missed a lot," Steinmeier said.

He noted that the year as European Capital of Culture is about learning from differences and developing forward-looking ideas together.

"Where the great democratic centre of our country creates space for itself, there is no room for those who reject democracy," Steinmeier added.

"Culture unites ... We are building the future together," he said.

The city carries a heavy legacy, still dogged by images of rioting right-wing extremists that went around the world in the summer of 2018.

On Saturday, extremists also staged a march on the opening day, while counter-protesters, advocating for diversity and respect, were present as well.

Police initially estimated "several hundred demonstrators on both sides." Later in the day, they said about 1,000 people showed up to protest against the right-wing group, which included about 400 participants.

A strong police of more than 1,000 officers were on hand to ensure safety and handle disruptions.

Mayor Sven Schulze defended the decision to allow the march, saying that freedom of expression and assembly was a "valuable asset."

This included allowing things which many may find intolerable, said Schulze: "I very much hope and wish that we can show where the majority stand today."

Earlier, Culture Minister Claudia Roth said: "With (its) impressive programme, Chemnitz and all 38 participating municipalities have the potential to create a cultural beacon that will be recognized throughout Europe."

Programmes were organized on several stages on Saturday, including a grand opening show at the Karl Marx Monument.

A rave was also planned at the town hall, while 120 people planned to pull a historic steam locomotive through the city to commemorate its rich industrial history.

EU Culture Commissioner Glenn Micallef said he was looking forward to a year full of celebrations showcasing the diversity, identities and values of the European Union.

Chemnitz is one of three European Capitals of Culture in 2025 alongside Nova Gorica in Slovenia and Gorizia in Italy.

It is the fourth time that a German city has held the title after West Berlin in 1988, Weimar in 1999 and Essen in 2010.

Some two million visitors are expected over the course of the year.

There is an exhibition on the Norwegian painter Edvard Munch, who spent time in the city in 1905, while a marathon route with music ranging from classical to electro creates the longest stage in the world.

Chemnitz aims to present itself as a vibrant and diverse city - complete with its scars and fractures, said Mayor Schulze: "You won't find a glossy brochure here."

There has been a push to modernize Chemnitz and other cities in the east to attract foreign visitors and investors since Germany's reunification in 1990.

As well as the cultural programme of events, 2025 will also champion Chemnitz's urban development, with around €100 million ($103 million) being channelled to various initiatives.

These include the transformation of a former factory ruin into a prestigious visitor centre through a public-private partnership.

An old tram depot is also being given a second life as a so-called garage campus with project, event and creative spaces.