A pyrotechnic - believed to be a smoke bomb - was set off outside the University of Sheffield this afternoon during a protest about controversial changes to lecturers' pensions.
It was let off in a crowd of dozens of people as the university's student union joined striking lecturers and support staff outside the Firth Court entrance.
They made their voices heard to support academics who have organised strike action in a dispute over proposals that they claim could leave them thousands of pounds a year worse off in retirement.
Dozens of tutors and university support staff formed picket lines outside Firth Court, the Hicks Building and the Arts Tower yesterday and today in what is the first of 14 days of planned strikes to be held in February and March.
Josh Armstrong, a 37-year-old student support worker, said: "The pension plan we have now provides for a secure financial future in retirement, but the new system does not.
"It is essentially a gamble based on how good or bad your money will do on the stock market."
The dispute centres on a proposal by Universities UK, which represents higher education institutions, to end the defined benefit element of the Universities Superannuation Scheme pension scheme.
UUK said the scheme is in deficit and the only way to make it sustainable is to change it from a defined benefit scheme, giving members a guaranteed income in retirement, to a defined contribution scheme, where pensions are subject to changes in the stock market.
But members of the University and College Union insist the existing scheme is performing well and claim the new set up would leave a typical lecturer almost £10, 000 a year worse off in retirement.
89 per cent of the 1, 300 members of the University and Colleges Union at Sheffield - made up of lecturers, researchers, student advisors, librarians and admissions staff - voted in favour of strike action.
This week's strike action will be followed by three further days between February 26 and 28, four days in March from the fifth to the eighth, and a full week between March 12 and March 16.
A University of Sheffield spokesman said: "USS, like many pension schemes, is facing challenges and we understand that changes to the scheme are necessary for it to remain affordable and sustainable. Following a series of over 35 consultation meetings, a joint negotiating committee of Universities UK and the Universities and Colleges Union, representing the collective employers and members respectively, voted through a proposal.
“We recognise that statutory timescales have pushed the USS trustee and the national negotiators towards this decision, however we will continue to encourage the employer representatives to undertake talks to provide a long term solution for the scheme which works for all parties."
He accepted that while there will be 'some disruption' this is not expected to be significant and there are plans in place to reschedule any cancelled lectures.