The number of anti-Semitic incidents reported in Austria increased more than 80 percent last year, the Austrian Forum Against Anti-Semitism said on Wednesday, according to the Reuters news agency.
The group said that reported internet postings denouncing Jews more than doubled during that time.
The forum, which began monitoring anti-Semitic incidents in 2003, said 465 incidents were recorded during 2015, over 200 of them being internet postings hostile to Jews.
The total number of internet postings reported to Austria's constitutional protection authority as offensive remained stable in 2015, but the number of postings liable to be used in criminal proceedings doubled compared to 2014, according to an interior ministry spokesman.
"The whole picture is terrifying," Oskar Deutsch, president of the Jewish Communities of Austria (IKG), said, according to Reuters.
Anti-Semitism has been on the rise in Europe in recent years, and Austria has seen its share of such incidents as well.
In October, a Jewish cemetery was defiled with Nazi symbols and anti-migrant slogans in western Austria, just weeks after similar attacks on a refugee hostel and Jewish museum.
Unknown perpetrators desecrated graves and buildings with a red pen in the Jewish cemetery of the town of Hohenems, close to the Swiss border.
And several weeks later, Austria's far-right Freedom Party dismissed one of its lawmakers, Susanne Winter, for an anti-Semitic Facebook post.
Winter had replied on the social network to a posting about a global conspiracy of "Zionist money Jews" with: "Nice, you have taken the words right out of my mouth ;-)."
IKG's Secretary General Raimund Fastenbauer told Reuters it was difficult to clearly tell who committed some anti-Semitic acts because offenders could not be identified and internet postings were usually anonymous.
But there was a clear trend of increasingly hostile behavior against the 15,000 Jews living in Austria from Muslims, he added.
"There is an increasing concern in our community that – if the proportion of Muslims in Austria continues to rise due to immigration, due to the refugees – this could become problematic for us," Fastenbauer said.