The Metropolitan Police has launched a hunt for a man who called for "dirty Jews" to "get beheaded one by one".
Footage shows the man, wearing a thobe, a traditional Islamic garment, confronting people in the street in east London as he made the vile remark.
One clip posted by Jewish community policing group Shomrim showed him leaning towards someone and shouting: "The Jews, you man are going to get beheaded one by one.
"You dirty Jews. Big up Palestine," he added. "F**k Israel, big up Palestine. Free Palestine, from the river to the sea."
Shomrim described the footage as a "horrific video... showing a gentleman threatening to behead Jews and much more."
It added it was "aware of the fact that the Orthodox Jewish community is exceptionally concerned about these threats".
It is "working closely" with Scotland Yard, it said - and hoped this might provide some reassurance to the community.
The Met has now confirmed officers were sent to Whitechapel Road in Tower Hamlets.
That was the same street - and same location, outside the East London Mosque - on which columns of masked Muslim men were seen chanting "Allahu Akbar" last year.
'The Jews, you man are going to get beheaded one by one,' the man says
|X/SHOMRIM
In a statement, the force said: "We are aware of this video, which was reported to police earlier on Friday afternoon.
"Officers have attended the scene and are carrying out urgent inquiries to identify the man involved.
"We understand that incidents like this cause significant concern and we take all reports incredibly seriously.
"Hate crime of any kind has no place in our communities."
Just days ago, police were forced to intoduce a dedicated team of 100 additional officers specifically for protecting Jewish people in London.
ANTISEMITISM IN BRITAIN - READ MORE:
Hundreds, if not thousands, of masked men marched through Whitechapel in October in exactly the same location as Friday's video
| GETTYThat came after a slew of attacks on Jews and Jewish sites across London.
The US, home to the world's second-largest Jewish population behind Israel, had to tell its citizens to use caution when visiting Jewish areas in Britain as a result.
Britain's terror threat level was upgraded from "substantial" to "severe" after two Jewish people were stabbed in Golders Green - where the King visited on Thursday in an historic show of support.
Security chiefs in the UK and in America believe an attack is highly likely within the next six months following an increase in "Islamist and extreme right-wing" ideology, MI5 said.
King Charles travelled to Golders Green to express his unwavering solidarity with the Jewish community in the wake of recent antisemitic violence
| GETTYIsrael's Prime Minister Benjamin Netanyahu also hit out at Britain's "weakness" in dealing with antisemitism, saying it "gaslights one antisemitic attack after another in London".
He added: "Words are not enough to confront this scourge. We demand and expect action by the British Government to protect the Jews of England and bring antisemites to justice."
But today, police are refusing to divert a massive pro-Palestinian march from a synagogue.
Jewish worshippers will be forced to walk through hordes of pro-Gaza protesters at the Palestine Solidarity Campaign rally if they want leave Westminster Synagogue in the west of the capital.
Karen Newman from the Board of Deputies of British Jews said worshippers "don’t want to have to run the gauntlet when they leave".
The Met said this week it recognised the impact the marches had had on the Jewish community but had decided against imposing similar restrictions on this occasion.
Anyone with information on the incident in Tower Hamlets has been asked to contact the Met quoting CAD 4911/15MAY26.