German Chancellor Angela Merkel has declared that "civil rights" will not be tolerated after radical right-wing riots over a murder in the Chemnitz city in the east.
For two days protests have erupted from hundreds of people in the GDR city center, since a German was stabbed to death on early Sunday.
The police have arrested a Syrian man and an Iraqi man for suspected murder.
A far-right football group called Kaotic Chemnitz called supporters to show. "Who is responsible?"
Video clips posted on Twitter show protesters calling "We are the people!". and "This is our city!"
Some reports also speak of aggressive demonstrators who persecute foreigners, though there are few details.
Police demonstrators have also thrown bottle bottles, which were reinforced by officials from other cities. [1
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It is unclear what triggered a fight allegedly struck on Sunday at about 03:15 (01:15 GMT) on the sidelines of a street festival that has now been canceled.
The 35-year-old victim was mortally wounded and died in hospital.
Two other German men with him, 33 and 38 years old, were seriously injured, police said.
The Syrian inmate is 23 years old and the Iraqi 22nd
Police have denied rumors about social media that the fight is linked to the sexual harassment of a woman.
How did the protests spread?
Initially, about 100 people gathered on Sunday for an event that happened without incident, according to news agency AFP.
However, about 800 people later gathered at the Karl-Marx-Denkmal Brennpunkt in the center of Chemnitz
The monument is a reminiscence of the city as a model socialist city in the former GDR when renamed Karl-Marx-Stadt has been.
Big, angry demonstration surprised the police
The freelance journalist Johannes Grunert told Spiegel Online that he had witnessed some demonstrators attacking people with bottles "who did not look German."
Pegida, the extreme right-wing street movement, demanded a new demonstration on Monday afternoon, while a right-wing AfD member, Markus Frohnmaier, tweeted: "If the state does not protect citizens anymore, then people go out on the street and protect yourself simple is that! "
" Today it is the duty of a citizen to stop the deadly "knife wandering"! "he wrote, referring to the influx of migrants in recent years. "It could have targeted your father, your son or brother!"
What exactly did Merkel's office say?
"We tolerate such illegal gathering and hunting of people who look different or have different origins and who try to spread hatred on the streets," Merkel's spokesman Steffen Seibert told reporters.
"This has no place in our cities and we, as the German government, strongly condemn it.Our basic message for Chemnitz and beyond is that there is no room for self-justice in Germany, for groups who hate the streets For intolerance and for extremism. "
Martina Renner, MP of the Radical Left, accused the extreme right of seeking to exploit the murder for political purposes
" A terrible murder, whose background is still unclear, is on most disgusting way instrumentalized for racial unrest in Chemnitz, "she said in a tweet.
Why? the problem of migrants so thorny?
In 2015, Angela Merkel decided to allow around 1.3 million undocumented migrants and refugees, mainly from parts of the Middle East, such as Syria and Iraq.
She and her allies were drafted into parliament for the first time in the last parliamentary elections last year, punished by the AfD's immigration hostility, gaining 12.6% of the vote and more than 90 seats.
Chemnitz is located in Saxony, a region where AfD and Pegida are particularly strong.
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