“We knew of the fact that violence was going to be used there. That was known for a long time in the [activist] scene,” Interior Minister Thomas de Maizière told ZDF TV on Wednesday morning.

“That's why the organizers can't act as if they aren't guilty today.”

Parties in the Bundestag (German parliament) agreed to hold an extraordinary debate on Thursday afternoon to discuss the outbreak of violence around the opening ceremony for the ECB's new building in central Frankfurt.

220 people hurt

Police said on Thursday morning that the total number of people arrested had risen to 26, including one activist who escaped arrest after attacking a police officer on Wednesday.

They were being investigated for breaching the law on demonstrations, breach of the peace and causing bodily harm.

Over the course of the whole day they said that 150 offficers were injured, some of them seriously.

Around 220 people in total were injured during the day.

SEE ALSO: Liveblog of Blockupy demo in Frankfurt

Most of the violence and property damage took place on Wednesday morning, when hooded activists, some of whom had travelled from abroad, attacked police barricades around the ECB and a nearby police station, where they set police cars alight.

Police responded with water cannon, tear gas and truncheons before kettling several large groups of protesters.

Failure to condemn

The violence dominated coverage of the demonstrations throughout the day, casting a pall over peaceful actions by the majority of demonstrators.

In the late afternoon, around 17,000 people marched from Frankfurt's Römer city hall to the Opernplatz (Opera Square) through the city centre.

But even that was marred by small groups lighting flares and throwing rocks at the police.

Social Democratic Party (SPD) leader for the state of Hessen and federal deputy leader Thorsten Schäfer-Gümbel told the Mannheimer Morgen newspaper that “I would have hoped that the organizers clearly distance themselves from the violence.

“Unfortunately they didn't do that.”

He particularly criticized Ulrich Wilken, member of the Hessen state parliament for Die Linke (Left Party) and organizer of the demonstration.

Christian Democratic Union (CDU) MP Thomas Strobl told Die Welt on Thursday that the violence in Frankfurt showed a need for a “cross-party pact to outlaw violence against police officers and emergency responders”.

Frankfurt firefighters had reported that their colleagues were also being attacked by demonstrators on Wednesday morning.

Media strongly critical

Across the political spectrum newspapers sharply condemned the violence.

Left-wing daily TAZ said that the calculation behind it “to achieve maximum exposure” was ultimately flawed “because the issue which Blockupy seeks to confront was the first victim of the flames.”

The Frankfurter Allgemeine Zeitung reserved its harshest criticism for the leadership of Blockupy.

“A 19-year-old can be excused for his naivete, he only wanted to demonstrate,” read its editorial. “The same cannot be said of Wilkens and his ilk.

"They knew exactly what they were doing. They toyed with death. First police cars burn, then people.”

The harshest criticism came from right-wing broadsheet Die Welt.

Left wing leaders in politics and media are “middle class children, inheritors of fortunes, self-benefactors, who want to be the good soldiers fighting aginst the evil," it argued.

"They march in line, singing workers songs. But the only working class children there are the police, who they attack with stones. There's your class struggle.”