One of the students in the sparsely populated class is heard replying, "shut the f*** up" before another stands up and goes to shut the door.
Students at Bangor this week pledged their support for their lecturers and organised their own demonstration outside the Deiniol library, in Bangor, this morning.
Universities UK, which represents the universities, said they were "making every effort to minimise the disruption to students" on Thursday and Friday.
"The marcher in question was violently tackled into a wooden table by another student", the group claimed.
"At this stage we are not certain how many staff are participating in industrial action but we are working hard to mitigate, as far as is possible, any impact of the proposed industrial action on our students whilst maintaining high academic standards".
Impact spoke with protesters at the picket line at the West Entrance of University Park Campus.
The tensions rose as lecturers at 57 universities across the United Kingdom hosted their first day of walkouts. The strikes will also take place on, February 23, Feb. 26 -Feb. "For many, this is a vital time in their studies", he said.
The dispute centres on proposals to end the defined benefit element of the Universities Superannuation Scheme (USS) pension scheme. They say the changes would leave them worse off in retirement by thousands of pounds a year.
But UUK says the scheme has said a deficit of more than £6bn. Security guards were overheard telling the police that automatic doors were broken during the surge.
Lecturers at 64 British universities, including Oxford and Cambridge, have begun a two day strike in a dispute over pensions.
The comments come after at least 15 vice-chancellors - including the heads of universities in Durham, Newcastle and Kent - publicly broke ranks and called for peace talks.
He added that there are scheduled discussions with the UCU on key issues with the USS.
Sally Hunt, general secretary of the UCU, said: "Universities UK needs to stop sending out mixed messages on whether it wants to talk or not. They want their fees compensated and they want them to get back to the negotiating table". It is important that they have fair and consistent terms and conditions of employment. "The sector is suffering from a serious image problem at the moment and staff and students deserve much better from their leaders than spin and subterfuge".
He said: "Many of my constituents, who teach at St Andrews, Dundee, Abertay and universities further afield, feel compelled to take this action to defend their pensions, despite displaying longstanding commitment to their universities and the education of students".
Speaking to Varsity, an anonymous global student expressed her frustration over both the conditions that forced staff to strike and its financial cost: "As an worldwide student paying extortionate fees, I find it disgusting that the staff have been driven to this necessity, and if possible will be contacting the university for reimbursement".
"The group of students, who carried banners and flares, cheered and shouted as they moved through the town around market square, down Senate House Passage and Burrell's Walk, then past the University Library to the Sidgwick site. It's the very spirit that underpins our University".