More than 1,000 people have turned out for a right-wing demonstration in the eastern German city of Chemnitz as local politicians met for a public forum to discuss violence in the city following a weekend stabbing with racial aspects.

"We continue to have a tense situation. Our officers are working in concentrated fashion, with the support of police from other states and the federal police," Saxony Interior Minister Roland Woeller told dpa.

"The aim is to maintain law and order with calm and discretion. We will not allow people who are prepared to use force to take over the streets," Woeller added.

State Prime Minister Michael Kretschmer was set to address the forum, and most of his cabinet were present.

Those entering the venue where the forum was being held were subjected to police controls. Police also kept the demonstrators and those attending the forum apart. The event was taking place in the rooms of the local football stadium.

The demonstration had been called by Pro Chemnitz, a right-wing group with some 18,000 followers that has been at the center of demonstrations in the city following the stabbing of a 35-year-old German in the early hours of Sunday.

The fatal stabbing - allegedly at the hands of a Syrian and an Iraqi - sparked a spontaneous rally the same day and a much larger rally on Monday that included clashes and random attacks on foreigners.

State police came under fire for policing the rally that drew 7,000 people with less than 600 officers.

The violence was fueled by false information on social media about the circumstances of the crime, including the claim that the victim had been defending a woman from the asylum seekers. Police debunked that claim, saying only that it had been a fight between two groups.

An arrest warrant for one of the alleged perpetrators was illegally leaked, prompting long-standing allegations to surface of links between Saxony police and right-wing groups.

The Saxony Justice Ministry said on Thursday that a law enforcement officer had been suspended from duty on suspicion of leaking the warrant related.

The document was published on the website of Pro Chemnitz, with certain details blacked out, as well as on a website of the anti-migrant Alternative for Germany (AfD) party.

The leak of the arrest warrant is punishable under German law with up to one year in prison.