(Reuters) - The war in Gaza has contributed to a sharp rise in antisemitic incidents in Europe, the European Union Agency for Fundamental Rights (FRA) said in a report released on Thursday.

An FRA survey conducted between January and June 2023 showed antisemitism was already high in Europe before the war began in October, and information collected from 12 Jewish community organisations since then showed a further rise, the report said.

"Jewish people have experienced more antisemitic incidents since October 2023, with some organisations reporting an increase of more than 400%," it said.

Three out of four Jewish respondents said they felt people hold them responsible for the Israeli government's actions and 80% felt antisemitism had grown in the European country where they live in the five years before the survey, it showed.

In the year before the survey was conducted, 90% of respondents had encountered antisemitism on the internet, with more than half experiencing it offline from people they know or in the media.

More than one-third were harassed during the same period because of their origin, most of them multiple times.

"Antisemitic harassment and violence mostly take place in streets, parks, or shops," the FRA said.

The survey said more than three-quarters of respondents hide their Jewish identity at least occasionally, and more than one-third avoid Jewish events or sites because of safety concerns.

The survey was carried out in 13 member states accounting for 96% of the EU's estimated Jewish population, which the FPA put at a little over 1 million.

About 1,200 people were killed and over 250 hostages seized in the Oct. 7 attack on Israel by Islamist militants, according to Israeli tallies. Israel's retaliatory offensive in Gaza has killed over 38,000, medical authorities in the enclave say.

A watchdog said last month that antisemitism had risen more than 80% in Germany last year. A network of NGOs monitoring Islamophobia and anti-Muslim hatred said in June that anti-Muslim incidents registered in Germany had also risen.

(Reporting by Michal Aleksandrowicz in Gdansk; editing by Milla Nissi and Timothy Heritage)