"It was animal-like behaviour - disgusting. I was shocked by what I was seeing," said Mr Stoll, 21. "They were banging chairs in front of us and shouting 'war ciminals', 'Nazis'. It was very intimidating. Esther was crying hysterically.
"My concern was for the students at the talk. If the protesters had got inside I wasn't sure what would have happened. I think it would have been a lot worse."
Ms Endfield, 20, said she had been terrifed.
"At one point I was against the door and Joseph was protecting me. I was crying because I was scared and didn't know what to do.
"This girl hit me and my phone dropped out of my hand. I was trying to film, she just came up to me and hit me on my arm.
"Some people were trying to punch the door to get into the room. They were very aggressive and angry. It was completely unacceptable.
More than 100 people had turned up to hear Mr Ayalon, who is touring UK campuses with left-leaning Zionist group Yachad.
The venue, at King's College London's Norfolk Building on its Strand campus, could only accommodate 60 people, leaving a group of around 30 pro-Palestinian activists outside the building.
They banged on the windows, held up flags and chanted slogans in an attempt to disrupt the meeting.
A smaller group managed to break into the building where they were confronted by Ms Endfield and Mr Stoll. Denied access to the room where the talk was being held, they set off fire alarms, threw chairs, and smashed a window.
One student who was at the talk said: "It was really quite frightening inside. There was banging on the ceiling - stamping."
Extra campus security guards and student union safe space officers had been drafted in but they were unable to stop the violence and called the police.
But when the 15 officers arrived they told Ms Endfield that they could not make protesters leave the building as it was private property.
The talk was halted 30 minutes before it was scheduled to end when when police decided to evacuate the building over fears of a fire risk. Mr Ayalon and participants were escorted out via a back entrance.
Police said later they were investigating an allegation of assault and criminal damage. No arrests have so far been made.
Professor Ed Byrne, King's College principal, has also launched an investigation into the incident.
A spokesman said: "Professor Byrne will also be writing to students to remind them that violent protest is totally unacceptable… We do not, and will not, condone the use of any form of violent protest."
King's College student union condemned the violence and said it would co-operate fully with the university's investigation.
In a post on its Facebook page the KCL Action Palestine society also condemned the violence.
"That the event escalated into a disruption was beyond our control and not incited by any member of our committee… We refute any involvement with what took place beyond this."
In a statement the Union of Jewish Students said: "There can be no justification for the events last night at KCL.
"The KCLSU Israel society were hosting an event about peace and were greeted by violence and intimidation. The fact that the police had to be called by the university in order to protect students from fellow students is a disgrace.
"It is however important to note that these acts were caused by a loud minority. Just 25 people managed to disrupt an event attended by nearly 60 while over 100 others who wished to hear the speaker and engage positively were turned away as there was no more space for them."
Universities Minister Jo Johnson said there "was no justification for violent intimidation that curtails free speech".
"Britain and Israel share many important academic links and speakers must be able to address meetings peacefully. Our universities should be safe spaces for students to expand their minds," he said.
In a statement Yachad said: "We condemn their actions in the strongest possible terms - attempting to shut down debate and dialogue runs contrary to the values of Yachad."
A statement from the Israeli embassy in London said the attempts to shut down the meeting were "shocking and shameful".
It added: "It reflects the fear that groups centred on hatred of Israel harbour toward those who promote dialogue and a peaceful solution in our region."
The embassy said it would consult with "the relevant British authorities, to ensure that visiting Israeli speakers are not harassed on UK campuses."
Mr Stoll, 21, who is campus director for Israel advocacy group Stand With Us, said the incident had showed him that "these guys are not interested in what anyone has to say. If you are Israeli you are essentially not welcome on campus."
