The identification last week of Islamic State militant 'Jihadi John' as Mohammed Emwazi, a graduate of the University of Westminster in London, has intensified concerns about whether young Muslims are being radicalised on British campuses.

The university said it was "shocked and sickened" by news that Emwazi had been named as the man in a black balaclava whose appearances in beheading videos have made him the defining image of Islamic State globally.

He is not the first Islamic extremist to have studied at a British university. According to the government, a third of those convicted of Islamist terrorism offences in Britain had attended universities.

Another high-profile case was Umar Farouk Abdulmutallab, the Nigerian "underpants bomber" who tried to blow up a plane on the way to Detroit in 2009. He is a graduate of University College London, where he was once president of the Islamic Society.

It is not known exactly how and when Emwazi was radicalised, but evidence has emerged suggesting that it is at least possible that his experiences at Westminster may have played a part.

"It would have been one of the universities at the top of my list if I'd been asked to pick one where he might have gone," said Rupert Sutton, director of Student Rights, an organisation that monitors extremism on campuses and campaigns against it.

Since November 2011, after Emwazi left Westminster, Sutton has been logging events at universities featuring external speakers with radical views. He said 22 such events had taken place at Westminster, more than at most other universities.

The speakers had included members of Hizb ut-Tahrir, an organisation that advocates unifying Muslim countries in an Islamic caliphate, and two students who were supporters of the group had been elected as student representatives.

The argument in favour of allowing radical speakers onto campuses, often put forward by academics, free speech campaigners and some politicians, is that it is better to air those views and challenge them than to drive them underground.

But critics of the practice say these events rarely take the form of genuine debates. Instead, speakers appear alone or with others who share their views, in rooms full of supporters who brook no dissent.

In addition, at Westminster and elsewhere, some Islamic Society events have been gender segregated, which is against Britain's equality laws and most university regulations.

"Under the camouflage of academic freedom and freedom of speech we are giving opportunities to extremists to traipse around campuses delivering a message of hate," said Anthony Glees of the Centre for Security and Intelligence Studies at Buckingham University.

'COULD HAVE HAPPENED ANYWHERE'

The Islamic Society at Westminster said on the day Emwazi was named that it was "not involved in any extremist activity" and denounced the "media fervour" that led to the cancellation of a controversial talk it had organised for that evening.

The guest speaker was Islamic scholar Haitham al-Haddad, whose presence on campus was opposed by thousands of students because of his alleged homophobic, sexist and anti-Semitic views. These had been misrepresented, the Islamic Society said.

The university's initial decision to allow Haddad on campus was questioned by students. One concern was that it was partly the responsibility of the university's interfaith adviser Yusuf Kaplan, who according to a student radio website had studied under Haddad.

Kaplan did not respond to emails from Reuters seeking comment. A university spokesman said there was a "robust policy" in place to assess the suitability of external speakers.

After the Emwazi story broke, the university cancelled the talk, citing "increased sensitivity and security concerns".

A second-year journalism student at Westminster told Reuters most students were dismayed that their university, which has 20,000 students from 150 countries spread across four campuses, was being portrayed as a hotbed of radicalism because of Emwazi.

"Lots of people think it could have happened at any London university. Does it matter that it was at Westminster?" said the student, who did not wish to be named because she did not want to be singled out for criticism by fellow students.

She said the vast majority of students, Muslim and non-Muslim, had moderate views, but she did think that if someone was attracted to radical Islamist ideas they would be able to find a small, like-minded minority.

Since Emwazi was named, a small number of former students have spoken out in the press about their own experiences at Westminster, some to criticise it and some to defend it.

James Tennent, who is studying Arabic at Westminster, wrote in the Independent newspaper that in three years on campus he had "never seen signs of an indoctrinating culture".

But Avinash Tharoor, who enrolled just after Emwazi left, wrote in the Washington Post that people felt comfortable there voicing dangerous and discriminatory beliefs because they were not being challenged effectively by peers or authorities.

Jamie Wareham, a former president of the LGBTI Society which represents students with minority sexual preferences, accused the university in an interview with the Guardian of turning a blind eye to homophobia. He said this was for fear of offending Muslim students from overseas who brought in high tuition fees.

Asked for a response, a university spokesman said: "We do not tolerate any extremist or discriminatory behaviour."

'TROJAN HORSE'

Fears that Islamic extremists are seeking to reach young people in their places of learning in Britain have focused not just on universities but also on schools.

Last year, a bitter controversy raged in Birmingham over allegations that hardline Muslims were targeting schools with high proportions of Muslim pupils in an orchestrated campaign to alter their ethos.

Schools inspection body Ofsted found that there was some evidence of a so-called "Trojan Horse" plot, but schools and members of the local community were outraged by the finding.

Last month, a secondary school in London, Bethnal Green Academy, was forced to defend itself after three of its pupils, all teenage girls, absconded to Syria to join Islamic State. The school said the trio were not radicalised within its walls.

Even the government is split about exactly how to handle the extremist threat. After Emwazi was named, a row broke out between Conservative ministers and their junior coalition partners, the Liberal Democrats, over guidance to universities.

The Conservatives wanted the guidance, which is being drawn up to help universities vet external speakers, to say that those promoting views "that support or are conducive to terrorism" should be banned. Their Lib Dem colleagues said only those crossing the line into advocating violence should be excluded.

Conservative Home Secretary Theresa May told the Sunday Times she expected universities to take a tougher stance in light of the news that Emwazi had studied at Westminster.

"If colleges and universities didn't realise before what we are up against, they should know now," she said.