(JTA) — Two Jews in Vienna said a man attacked them with pepper spray after the assailant and four others hurled anti-Semitic insults at them near a far-right rally.

The attack occurred on the night of Jan. 30 on Karntner Street, which is located about 500 yards from where far-right supporters and politicians that night were having their annual ball at the former imperial palace of Hofburg, the news website diepresse.com reported Sunday.

Dozens were arrested in riots that erupted after thousands of people showed up to protest the holding of the annual event of Austria’s FPO party.

During the attack against the two Jews, who were not named, five men shouted at them anti-Semitic insults including “fucking Jews,” and “Jewish pigs,” according to Julian Poschl, a freelance journalist who witnessed the incident. After the insults, one of the five men sprayed pepper spray in the face of one of the Jews.

The two men were not wearing clothing or symbols that identified them as being Jewish.

Austrian police told Die Presse they were investigating the incident, which the alleged victims reported, but could not confirm the attack was anti-Semitic in nature.

“Whether there has been an anti-Semitic insult, I cannot say,” a police spokesperson told Die Presse. “The perpetrators fled immediately after the attack, we could not ask the other side.”

The Jewish Community of Vienna has condemned the hosting at the Hofburg Palace — a privately-owned complex with a commercial conference center which nonetheless houses some government entities — of the event by the FPO party, which the community regards as a racist entity.

The community’s president, Oskar Deutsch, called the hosting “shameful” in a statement sent out Sunday.