If police can identify any individuals they can be charged under Austria’s Prohibition Act, which aims to suppress a potential revival of Nazism.
The 400 Pegida supporters who marched on Monday evening were dwarfed by a colourful counter-demonstration more than ten times larger, according to police estimates.
The two groups were kept apart by around 1,200 police, and there were no incidents of serious violence reported. However, 13 people were arrested for civil disorder and one case of bodily injury.
All 13 have since been released and charged, police spokesman Roman Hahslinger told the Austrian Press Agency. He added that some of the extreme-right wing supporters were already known to police.
Pegida (Patriotic Europeans Against the Islamisation of the West) spokesman Georg Immanuel Nagel told AFP that more of the group's supporters had turned up than expected, and said a second march is planned in Linz on Sunday February 8th, which would begin at 3.30pm.
Nagel was not available for comment on Tuesday, and it’s not clear if he plans to organise further marches in Vienna.
On Facebook he commented that the first march had been “a great success”, and that even if “things hadn’t been optimal, we have sent a clear signal for more public participation and transparency!”
If police find that Pegida supporters were violating the Prohibition Act they could ban any subsequent marches.