An anti-islamist rally organised by far-right group the English Defence League in Aarhus last weekend was far outnumbered by anti-fascistdemonstrators.
While the EDL had voiced hopes that the demonstration would be attended by some 700 of its supporters, in the event just 150 turned up.
Meanwhile, the rally attracted a 5,000-strong counter-demonstration.
Despite efforts by the East Jutland police to keep the two groups separate, around 100 counter-demonstrators broke away from the main march and made their way to a park in the centre of Aarhus, where the far-right groups had assembled.
The counter-demonstrators hurled paving slabs, stones and bottles at the EDL supporters, and four police officers were injured trying to control the crowd.
No-one from the far-right rally was arrested, but 89 counter-demonstrators were taken into custody. Five were jailed for two weeks for injuring police officers.
Among Danish, English and German flags, Israeli flags were waved by the EDL supporters.
Ela and Henrik Chievitz, who together organise the Danish Israeli Union of Aarhus, said they found the day's events disturbing.
"It's the wrong thing to do, to use the Israeli flag in this way," said Mr Chievitz. "I'm expecting this event to be used against Israel and the Jewish community and I think it could spark tension."
Mrs Chievitz added: "It's already difficult for me to walk in Muslim areas because I wear a Magen Dovid and when there's provocation like yesterday, it makes things worse."
A spokesperson for East Jutland Police Force said he knew of no
evidence that the use of the Israeli flag in this context had inflamed the
situation.
There are around 2,400 Jews affiliated to the main synagogue in Copenhagen and 8,000 Jews are estimated to live in Denmark.