London's Jewish community has been on edge since Hamas's attack on Israel earlier this month, with security increased at synagogues, schools and other buildings.
"People feel vulnerable and people feel frightened, and right now the recorded incidents of anti-Semitism are a record," said Raymond Simonson, chief executive of the JW3 arts, culture and entertainment venue in the north of the UK capital.
"There's never been this many incidents... in the UK as there have been in the last 20 days," he told AFP.
"We've doubled our security. The Metropolitan Police have quadrupled their visits... to make sure we're safe. It's the only way we can do it," he added.
JW3 last Friday set up an installation, "The Empty Shabbat Table", to keep alive the memory of the more than 200 hostages Israel says were taken by Hamas.
Simonson said the attack made him realise that he had taken for granted the Jewish day of rest, which he has always marked with his family.
Around a huge table were more than 200 empty seats, including high chairs, with the name, age and nationality of the captives plus the word "kidnapped".
Israel says more than 1,400 people, mainly civilians, were killed after Hamas militants stormed across the Gaza border on October 7 in the worst attacks in Israel's history.
The health ministry in Hamas-run Gaza says more than 8,300 Palestinians have been killed by Israel's relentless retaliatory bombardment since then, 3,457 of them children.
In London, where there have been several large-scale protests in support of Palestinians in Gaza, the Met said it had recorded 408 anti-Semitic offences between October 1 and 27.
That compares to just 28 in the same period last year, the force said on Friday.
At the same time, there have been 174 Islamophobic offences compared to 65 in the same period in 2022, it added.
- Patrols -
Simonson said Jewish people in the UK were shocked at the attack, and remained stunned and exhausted three weeks later, spending their time monitoring the news and keeping in touch with friends and family in Israel.
Marielle, a 49-year-old French national who has lived in London for 18 years and did not want to give her family name for safety reasons, said the atmosphere was "very anxiety provoking".
"At our daughters' secondary school, the headteacher and members of the teaching staff are stationed on the route from the underground to the school" to make sure their children are not attacked, said the financial analyst.
In the wake of the Hamas attack and Israel's response, several Jewish schools in London were shut temporarily.
Local synagogues and faith schools also called for more volunteers from members and parents to boost their security.
In Stamford Hill, a multicultural area of northeast London which is home to many Orthodox Jews, the local Shomrim (community safety group) has extended its patrol hours.
"There have been a number of low-level incidents," said Shomrim chairman Rabbi Herschel Gluck.
"But these low-level incidents, of course, have traumatised people to a much greater degree than the normal times," he added.
"I think, in normal times, many people would not have reported these incidents. But in today's atmosphere, these touch people a lot deeper," he said.
Gluck said he feared a possible "lone wolf" attack but was quick to point out that Jews and Muslims live side by side relatively harmoniously in London.
On one street, he said, there are 10 synagogues and a Jewish school alongside a mosque, a Muslim cultural centre and a Muslim school.
"People just live together without any tensions, thank God," he said. "I think that this is an inspiration for many other places."