BERLIN - Germany's foreign minister said at an international conference on anti-Semitism on Thursday that "hatred of Jews" was on the rise once more in his country and across Europe, fueled by spiraling violence in the Middle East.Frank-Walter Steinmeier said Germany's Jews were subjected to threats and attacks at pro-Palestinian demonstrations, and the conflict between Israel and Hamas in Gaza must not be used as justification for an anti-Semitic behavior.As well as slogans like "Gas the Jews!" during some marches, in July at the height of the 50-day Gaza war petrol bombs were thrown at a synagogue in Wuppertal which had been burnt down on Kristallnacht - a Nazi attack on the Jews in 1938 - and rebuilt."Bold and brutal anti-Semitism has shown its ugly face again," Steinmeier told an Organization for Security and Cooperation in Europe (OSCE) event.Among the speakers was Karen Polak, from Amsterdam's Anne Frank House, who told delegates there had been "lots of outspoken violence against Jews who obviously have no responsibility for the policies of the state of Israel".Frank, a Jewish girl who died in Bergen-Belsen concentration camp in 1945, wrote a posthumously published diary while in hiding that has helped teach post-war generations about the Holocaust - the murder of six million Jews during World War Two."You see it time and time again - when tension in the Middle East rises, anti-Semitic incidents in Europe rise," said Polak.With far-right parties making strong gains in May's European Parliament elections, the OSCE said all communities and faiths needed to be on the alert. According to an EU survey, one in four Jews living in the bloc report having suffered an anti-Semitic incident.Pinkas Kornfeld, a Jewish community leader from Belgium, blamed the rise in hate crime on "people who want to import the Middle East conflict to Europe" and political extremists on the European far right and far left.Samantha Power, US Permanent Representative to the United Nations, said anti-Semitic attacks "are not only a threat to the Jewish community, they are a threat to the larger project of European liberalism and pluralism".Praising EU leaders such as Germany's Angela Merkel for her firm stance, she asked why fewer countries were attending than at the first OSCE anti-Semitism conference 10 years ago."Make no mistake - we have a problem," she said.