Anti-Semitic slogans as well as angry protests against Arab leaders were heard as around 200 hundred people demonstrated in Malmö on Friday.
The demonstration took place in reaction to US president Donald Trump's decision to move the American embassy from Tel Aviv to Jerusalem and recognise the latter city as the Israeli capital.
"We take this kind of thing seriously in general. It could be an incitement for people to commit crimes," police communications officer Calle Persson told TT.
Demonstrators shouted "we want our freedom back and we're going to shoot the Jews", among other slogans, according to a report by Sveriges Radio.