One young woman with the Chabad group who has asked to remain anonymous told the JC the men appeared to be mocking them.
When the Jewish group tried to ignore them, they became more intimidating.
Rabbi Shneor Glitsenstein of the Chabad Israeli Centre Golders Green was on the bus with his group.
He told the JC the men starting shouting “Free Palestine” at them.
To avoid any escalation, Rabbi Shneor told the group get back onto the bus. At this point the men became increasingly aggressive, attacking the vehicle while it waited for a gap in the traffic to drive away.
A shocking video of the incident shows the men hitting the bus while passengers tell the driver to leave.
“Go, go,” one passenger shouts, while another calls out: “Drive, drive.”
Two of the men take off their shoes and begin slapping the windows of the bus with the soles.
The men then begin spitting at the windows and hurling inaudible shouts at the bus.
Two of the men raised their middle fingers at those on board.
As the bus finally drives away one man runs alongside it, punching the window with the side of his fist.
The woman on the bus told the JC she believed the assault was “definitely” because the group were Jewish.
“There is no doubt about that,” she added.
“No one else in the street was being targeted.”
She said the Israelis on the bus were “shocked and disgusted” by the attack given their lack of experience of antisemitism.
Rabbi Shneor said it was “not something you expect to see in the middle of London. You want to feel free and secure in London”.
A member of the Chabad group put in a complaint to the police shortly after the incident.
The rabbi said the scene reminded him “of Gaza”, in an apparent reference to the “hate convoy” demonstrations that took place in north London in May during the conflict between Israel and Hamas.
Insisting he and his group would not be cowed, Rabbi Shneor said: “The mission of Israel is to bring light and goodness. We don’t want to let them win by being intimidated.”
The video, originally broken by Campaign4Truth, has now racked up hundreds of thousands of views online.
The Community Security Trust (CST) said in a tweet that “two of the victims of this appalling incident” have reported it to them. They added: “We will ensure they receive appropriate support and we’ll work with the police to try to ensure the perpetrators are identified and brought to justice.”
Public officials have condemned the footage on social media with Culture Secretary Nadine Dorries calling it "chilling" and London Mayor Sadiq Khan urging Londoners to report any information they may have about the incident.
The Metropolitan Police have been contacted for comment.
