There has been a “massive increase” in antisemitic incidents in London since the Hamas attacks on Israel, the Metropolitan Police said.
Between 30 September and 13 October there were 105 antisemitic incidents and 75 offences.
In the same period last year, there were 14 antisemitic incidents and 12 offences.
The PM called the rise “disgusting”, adding extra funding had been given to protect Jewish institutions.
Hamas launched an unprecedented attack on Israel on Saturday, killing more than 1,300 people and taking up to 150 hostages. More than 1,500 people have died in retaliatory strikes on Gaza.
Met Police deputy assistant commissioner Laurence Taylor said antisemitic incidents over the past week included intimidation outside synagogues and loudly playing German military music.
He added the force had also seen an increase in Islamophobic incidents, “but nothing like the scale of the increase in antisemitism”.
The deputy assistant commissioner added the Met had put a “very significant policing operation” in place and was seeking to support and reassure communities in London.
“We have got more than a thousand officers dedicated to providing reassurance and security patrols across vulnerable locations,” he said.
“Those patrols will continue into the foreseeable future”.
The Met is urging anyone who is subject to a hate crime or worried about their safety to contact the police.
Speaking in Sweden on Friday, Prime Minister Rishi Sunak told reporters he had chaired a meeting with police chiefs and the Community Securities Trust – a charity which provides security advice for British Jews – to “make sure everybody in our Jewish communities can feel safe”.
“Intimidating or threatening behaviour will not be tolerated,” he said, “it will be met with the full force of the law”.
Three Jewish schools in north London closed for the day on Friday, with some citing planned protests in support of Palestinians.
DAC Taylor said the Met had been speaking to faith leaders across the board, adding that they had more than 30 dedicated schools officers who are visiting schools and talking to parents.
One officer held a meeting with 2,000 parents earlier this week to talk about their concerns.
DAC Taylor confirmed that there had not been any specific threats to schools in London.
The Metropolitan Police said it is anticipating thousands of people will attend a pro-Palestinian protest in London on Saturday – with more than a thousand officers set to be on duty.
Home Secretary Suella Braverman has said she expects the police to “use the full force of the law” against displays of support for Hamas.
Ahead of the weekend DAC Taylor said the law was very clear that anyone waving a flag in support of Hamas or other proscribed organisations would be arrested.
Anyone possessing or waving a Palestinian flag without any other context would not be committing any offence, but if its associated with other actions they could be, he added.
