British universities are being targeted by Islamic extremist groups looking for recruits
A conference of chief security officers will hear that religious radicals remain active on campuses and have infiltrated at least 20 institutions.
Prof Anthony Glees, of the Centre for Intelligence and Security Studies at Brunel University, will say the threat must be "urgently addressed".
The Government has issued guidance to universities over how to deal with the threat. Bill Rammell, the higher education minister, said it was "real, but not widespread."
But Prof Glees will tell a conference of the Association of University Chief Security Officers in Exeter that there is a danger of complacency.
"We must accept this problem is widespread and underestimated,'' he will say. "Unless decisive action against campus extremism is taken, the security situation in the UK can only deteriorate."
Prof Glees believes that al-Muhajiroun, the disbanded extremist group, has infiltrated universities, and followers of Omar Bakri Mohammed, its founder, are still operational in several campuses. Another radical group, Hizb ut Tahrir, is also active in universities and colleges.
Prof Glees produced a report last year that listed more than 20 institutions where "extremist and/or terror groups" had been detected.
They included some of the most prestigious universities in the country, such as the London School of Economics and Manchester University.
Prof Glees was concerned that universities were so desperate to fill places with overseas students that they no longer vetted foreign applicants properly or even required hard proof of identity.
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