In Los Angeles, a man screaming "kill Jews" attempts to break into a family's home. In London, girls in a playground are told they are "stinking Jews" and should stay off the slide. In China, posts likening Jews to parasites, vampires or snakes proliferate on social media, attracting thousands of "likes".

These are examples of incidents of antisemitism, which have surged globally since the attack by Hamas gunmen on southern Israel on October 7 and the subsequent war on the Islamist group launched by Israel in the Gaza Strip.

"This is the scariest time to be Jewish since World War Two. We have had problems before, but things have never been this bad in my lifetime," said Anthony Adler, 62, speaking outside a synagogue where he had gone to pray in Golders Green, a London neighbourhood with a large Jewish community.

Adler, who runs three Jewish schools, temporarily closed two of them after October 7 because of fears of attacks on pupils and has beefed up security at all three. "The biggest fear is that there will be a random attack on our community, on our families and our children," he said.

In countries where figures are available from police or civil society groups, including the US, Britain, France, Germany and South Africa, the pattern is clear: the number of antisemitic incidents has gone up since October 7 by several hundred per cent compared with the same period last year.

In some countries, such as the US and Britain, Islamophobic incidents have also increased since October 7.

One common thread is that anger over the deaths of Palestinians as a result of Israel's bombardment of Gaza is invoked as a justification for verbal or physical aggression towards Jews in general.