The number of anti-Semitic incidents reported in Austria increased more than 80 percent last year, with reported Internet postings denouncing Jews more than doubling, an Austrian group said on Wednesday.

Jews across Europe have warned of a rising tide of anti-Semitism, fueled by anger at Israeli policy in the Middle East, while far-right movements have gained popularity because of tensions over immigration and concerns following militant Islamist attacks in Paris and Brussels.

The Austrian Forum Against Anti-Semitism, 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.

The European Union Agency for Fundamental Rights (FRA) urged the European Union and its member states in January to increase efforts to combat widespread anti-Semitic cyber hate, arguing that anti-Semitism in the region did not show any sign of waning.

IKG's Secretary General Raimund Fastenbauer said 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, the Jewish community representative said.

"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.

Austria has mainly served as a conduit into Germany for refugees and migrants from the Middle East and Africa but has absorbed a similar number of asylum seekers relative to its much smaller population of 8.7 million.