Violent protests hit the streets of the German city of Frankfurt Wednesday as anti-austerity protesters rallied against the opening of a new building for the European Central Bank (ECB).

Local police reports said that cars had been set on fire and incendiary missiles had been hurled at both the police force and firefighters. A total of seven police cars have been set on fire with a total of 8 police officers injured in the clashes, according to NBC News. A further 80 officers are being treated after attacks with an unidentified "irritant", the police told the news agency. Fire brigade tweet



Riot police clash with protesters dressed as clowns on the opening day of the European Central Bank (ECB) in Frankfurt am Main, western Germany, on March 18, 2015. DANIEL ROLAND | AFP | Getty Images

"The atmosphere is highly aggressive," police spokesperson Tessa Koscheg told NBC News.

"We are recommending to the public to avoid the city center at the moment," she said, adding that police were facing "several hundred" protesters.

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Up to 350 posters have been detained as the violence begun late Tuesday evening, according to a press release by the Frankfurt police, who also estimated the resulting damage could be tens of thousands of euros.. The anti-austerity group at the heart of the protests, called Blockupy, organized the protest against the opening of the new ECB building in the center of Frankfurt's financial district.

A woman cycles by a burning barricade as the ECB building is seen on the left, on the opening day of the European Central Bank (ECB) in Frankfurt am Main, western Germany, on March 18, 2015. DD ANDERSEN | AFP | Getty Images