London Guildhall University closed all its buildings and sent staff home for the day last Friday, on the advice of the police, following a demonstration by the Muslim fundamentalist group Hizb ut-Tahrir.
Confrontations have also taken place on other campuses as the group has sought to recruit new members at freshers fairs.
At LGU, Hizb ut-Tahrir was protesting at the treatment of a Muslim woman who had alcohol spilt over her in the student union by members of the rugby club.
A statement from the union said: "Three sabbatical officers spoke to the student, and she was informed that if she was not satisfied by the apology by the rugby club members, she could pursue the matter through the relevant disciplinary channels." So far the woman has not contacted the union, and it is therefore unable to take further action.
In a statement Hizb ut-Tahrir said the incident was part of a "hate campaign orchestrated almost exclusively by the Union of Jewish Students and their lackeys in the National Union of Students."
Hizb ut-Tahrir, the Islamic Liberation Party, is banned in most Middle East countries. In 1991, its leader called for the assassination of prime minister John Major. It has been banned from a number of university campuses and student unions for its anti-Semitic and homophobic views. The group regularly calls for attacks on Jews and urges Muslims to destroy the state of Israel.
According to the National Union of Students, which has a "no platform" policy on Hizb ut-Tahrir, the group has also caused disturbances at Cambridge's freshers fair.
This week Ghassan Karian, president of the University of London Union, which also has a "no platform" policy, ejected the group from the university's freshers fair.
"The group were parading under the name of the Muslim Education Society," he said. "They were displaying leaflets which are normally distributed by Hizb ut-Tahrir and we found leaflets with the Hizb ut-Tahrir logo on being delivered to the stand in boxes." After the group was expelled from the building, they set up on the street outside, and exhibited Hizb ut-Tahrir leaflets.
Two students who were on the stand, one from the School of African and Oriental Studies and one from University College, refused to give their names, or confirm or deny any connection with the group.
Mr Karian said: "We are not discriminating against Muslims, but we are keen to ensure that organisations that seek to persecute other groups do not have a platform."