Germany has banned a left-wing extremist online platform it said incited and fuelled violence during protests at the G20 summit in Hamburg in July.

The crackdown has made the use of the far-left website “linksunten.indymedia“, which allegedly played a key role in linking activists, organising and stirring violence in Hamburg, a criminal offence.

Interior Minister Thomas de Maizière said the website was being shut down for “showing hate” and encouraging behaviours which “trampled human dignity”.

The ban of one of the most influential left-wing extremist platforms to operate in Germany will cover not only the website but also the network’s email and social media accounts and its licence to operate as an organisation. The site came offline on Friday morning.

With a month to go before German voters go to the polls to chose their next Chancellor, authorities do not want to see a repeat of the violent protests led by anarchists and far-left activists which erupted in Hamburg as the country was hosting the leaders of the G20.

Peaceful protests on the fringe of the summit descended into violence in the northern port city with police clashing with a hard core of masked protesters hurling bottles and stones, looting shops and setting cars on fire. Police said about 500 officers had been injured in the clashes.

The Die Zeit newspaper reported two of the platforms’ journalists were denied accreditation to enter the summit.

Angela Merkel’s government faced the embarrassing prospect of having to lock down Germany’s second largest city amid a visit by world leaders including Donald Trump, Emmanuel Macron, and Theresa May, along with the world’s media.

Thomas de Maizière, a member of Ms Merkel’s CDU party, said shortly after the protests that the activists involved should be made to wear electronic tags.

Linksunten was founded in 2009 and has been operating as an “association” rather than a news organisation to get around constitutional protections on freedom of expression.

The extremist platform, which published instructions to make Molotov cocktails, has been described by the German government as the organiser of violent actions against both state infrastructures and private facilities, using fire fights and harming people under the cover of anonymity.

Mr de Maizière said the website incited violence against police with officers previously being threatened and called “pigs” and “murderers” and that letting the site run would “legitimise violence”.

G20 Protesters take Hamburg Show all 8 1 /8 G20 Protesters take Hamburg G20 Protesters take Hamburg German riot police use water cannons against protesters during the demonstration during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg German riot police clash with protesters during the demonstrations during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg Riot police move in through the smoke from a smoke bomb during the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg Riot police use water cannon to put of burning bins as a protester runs off after the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg Protesters throw beer bottles as they shield themselves from water cannon spray during the "Welcome to Hell" rally against the G20 summit in Hamburg, northern Germany AFP/Getty Images G20 Protesters take Hamburg A firefighter works at the scene where a number of cars burnt down during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg The interior of a burnt down car is seen as firefighters work in the background during the G20 summit in Hamburg, Germany REUTERS G20 Protesters take Hamburg German police remove a protestor who is blocking a street at a demonstration during the G20 summit in Hamburg, Germany REUTERS

He added the ban would enable the break down the structure of the association, seize its assets and “send a clear signal that we are consistently opposed to left-wing extremism on the internet.

“This is the expression of a behaviour that tramples human dignity,” he said. “This is absolutely unacceptable and incompatible with our liberal democratic order.

“For radical, violent extremists – whatever their orientation – there is no place in our society,” said Mr de Maizière.

Authorities in the southwest region of Baden-Wuerttemberg searched properties linked to at least three of the site operators, AFP reported.

This is the first ban of a left-wing extremist platform by the German federal government. Linksunten’s far-right counterpart Altermedia Deutschland was outlawed in January 2016.

Linksunten operated as a sub-domain of Indymedia, an international network of anti-globalist, anti-capitalist and anti-fascist activists, hackers and journalists, with the aim to create an alternative movement.