Both Jewish and Muslim families have “real fears” about rising intolerance in Europe following the Paris and Copenhagen attacks, Ed Miliband has said.
The Labour leader called for European leaders to show “unity of purpose” and work more with social media companies like Facebook and Twitter to counter extremism.
Mr Miliband spoke out in the wake of the attacks in the Danish capital, where a gunman shot dead a film director at a cafe event on free speech and then killed a Jewish security guard at a synagogue.
The atrocity bore resemblances to the Paris attacks, when several people were killed by Islamist extremists at the satirical magazine Charlie Hebdo and at a Jewish supermarket.
The British Jewish community have called for more protection, fearing copycat attacks on UK soil.
Mr Miliband said the attacks would provoke fear among people of all backgrounds.
At an event in Lincoln, he said: “There is real fear among Jewish families, among Muslim families, among people of all backgrounds about the rising intolerance that we see.
“We have to recognise that – but recognising it is not enough.
“Europe’s leaders have got to show a unity of purpose in tackling these issues.
“I don’t think we can just walk by on the other side when we have seen the kind of events we’ve seen in Copenhagen.”
The Labour leader called for better work within communities to “nip in the bud” the radicalisation of young people, alongside cross border working among European countries.
Mr Miliband also said ministers need to engage with social media to try and prevent radicalisation online.
He said: “I think that the freedom of social media is incredibly important but we have to look at the ways we can counter this stuff online.”