Police are investigating allegations of antisemitism after a lecture by a controversial speaker at the London School of Economics descended into chaos and 30 Jewish students walked out in protest.

The subject addressed by Abdel Bari Atwan, editor-in-chief of London-based Al-Quds Al-Arabi newspaper, was "How much influence does the Zionist lobby exert in the US and UK?"

During the lecture, Mr Atwan, who had been invited by the Palestine Society, allegedly accused Jewish students of "bombing Gaza", referred to the "Jewish lobby" and refused to condemn Hamas, saying: "Would you want me to condemn those who are resisting the occupation?"

He has previously been captured on video in 2007 on MEMRI TV saying: "If the Iranian missiles strike Israel - by Allah, I will go to Trafalgar Square and dance with delight if the Iranian missiles strike Israel."

Following the event, students from the Israel Society, who had been refused the opportunity of providing their own speaker to balance the panel, met the Dean of Undergraduate Studies, Dr Janet Stockdale. She assured them the event would be investigated and that procedures for such meetings would be reviewed.

The Union of Jewish Students had agreed a set of conditions with LSE's student union beforehand, including the videoing of the event and chairing by an independent academic.

Carly McKenzie, UJS campaigns director, said organisers had failed to meet these assurances: the filming was left to the Palestine Society and has not been made public.

The chair was a senior LSE lecturer who is co-convener of the British Committee for the Universities of Palestine (BRICUP), Professor Martha Mundy. She has written extensively on her support of an academic boycott of Israel.

An official complaint has been lodged with the university about her conduct by UJS and the Israel Society.

"We feel let down by the student union," Ms McKenzie said. "They reneged on their assurances...Their attitude following the event has been both lethargic and inadequate.

"The comments made by Atwan were in clear breach of the student union's antisemitism policy as well as wider university and civic codes.

"These shocking incidents highlight the importance of better regulation of extremist speakers on our campuses."

One of the students at LSE, contacted police after the meeting, saying he had felt concerned for his safety. "The question and answer session is when things got very nasty," he said. "A question was asked by the audience regarding what Atwan said on MEMRI TV. He managed to avoid answering this properly, and when I asked for an answer, I was shouted down by both the chair and Atwan.

"Atwan then proceeded to point at several members of the audience, including me, and shouted 'You bombed Gaza' to each one.

"I felt very intimidated by being shouted at by two people at the same time, especially as one of them was a lecturer from my university who is supposed to have a duty of care for my wellbeing."

One member of the audience accused Jewish students of being Nazis and after the lecture told the Jewish student directly that his Israeli family were Nazis and that he was part of the "Israeli police".

Gabi Kobrin, president of the LSE Israel Society, who walked out of the event, said: "I felt extremely intimidated, uncomfortable and fearful. As I left, people were jeering and saying "go get her".

"LSESU Palestine Society has shown it has no regard for student welfare, good campus relations nor a peaceful resolution to the conflict in the Middle East.

"Our repeated attempts to work constructively with Palestine Society have been rejected in favour of it pursuing an aggressive, alienating and one-sided agenda."

In March, the Board of Deputies launched a five-point strategy to combat campus extremism which included monitoring visits from extremists with the co-operation of UJS. But Jonathan Arkush, its senior vice-president, said deputies were not aware of the LSE meeting beforehand.

He said: "Up until now LSE has rejected all attempts to bring home to it the dangers of hate speech on its campus. Perhaps now they will finally learn that lesson.

"The Board immediately offered UJS its backing in meeting LSE's academic leadership and will follow the outcome of such discussions closely.

But the Board was heavily criticised for its inaction. Ronnie Fraser, chair of the Academic Friends of Israel, said: "The Board needs to pull its finger out and get its five-point plan up and running." And academic Professor Geoffrey Alderman observed: "It's pretty pathetic that the Board didn't know this was going on. Some serious questions should be asked about why."

Professor Eric Moonman, president of the Zionist Federation, said: "We can't leave it up to the students to battle in a way that most adults would hesitate to get involved in. It requires a professional organisation to monitor these events seriously and neither the Board nor anyone else is doing that."

Raheem Kassam, the Muslim director of Student Rights, a counter-extremism pressure group that monitors activities on campuses, said that not enough action is taking place to prevent hate speakers. "Ministers don't understand the threat of what happens," he said.

"It's in the face of other priorities like the NUS protests, and makes this seem like a small-minded matter that doesn't affect anyone.

"They and heads of universities don't realise that these events are causing such deeprooted hatred that lasts a lifetime.

"The universities deny it to protect their reputation. It is in the LSE's interest to play this down."

Israeli Ambassador Ron Prosor said: "To invite Atwan to a British university should be inconceivable.

"That in 2010, situations are allowed to develop where Jews are called 'Nazis' on British campuses, should appal and concern Britons in equal measure.

"The deep freeze may be over but the cold response by a British university to vile hatred and antisemitism on campus continues.

"The raising of tuition fees has seen thousands of students take to the streets in protest. The raising of extremism on campus should see millions outraged."

Universities UK, which hosts a working group investigating ways to tackle hate speakers on campuses, is now not expected to publish its report until 2011.

That is more than a year since the group was set up after the arrest of former University College London student, Umar Farouk Abdulmutallab, for allegedly attempting to blow up a plane flying to Detroit.