Students from across Wales protest over fees and cuts
Students across Wales have joined in protests about increased tuition fees and education cuts.
About 300 students in Cardiff marched on the city centre before 50 occupied a lecture theatre at Cardiff University.
Pupils at Monmouth Comprehensive and students and lecturers at Aberystwyth University also took action.
The protests come as the body that funds Welsh universities voiced concerns about the financial sustainability of almost half of them.
The Higher Education Funding Council for Wales (HEFCW) said five of the country's 11 institutions faced an uncertain long-term future.
Concerns were registered about the long-term future of six institutions, while none were found to be high risk and six were deemed to be at low risk.
Meanwhile, Higher Education Wales said there was a need to assess the level of contribution graduates in Wales make.
University funding was cut by 12% over three years in the assembly government's draft budget last week.
The UK government wants to increase tuition fees for universities in England up to £9,000 per year.
The assembly government is expected to outline its position before Christmas.
Student protester Sam Coates said police were called to the main building at Cardiff University where a demonstration was being held.
Students staged a sit-in at the Shandon lecture theatre.
Mr Coates said police and security blocked the entrance to the theatre to stop any more students getting in.
Students also marched along Park Place towards the city centre, bringing traffic to a standstill.
A Cardiff University spokesperson said: "A group of approximately 50 people have occupied Cardiff University's large Shandon lecture theatre this afternoon.
"At present there is no disruption to normal university activity and the university is presently monitoring the situation."
At Monmouth Comprehensive, sixth form students staged a protest with banners.
Pupil Anna Burn said: "I think it's really important that we show the government exactly how we feel because if they understand how passionate we are about education, they are much more likely to listen in the future."
Students and lecturers at Aberystwyth University held lectures and seminars on the streets in the town's Bank Square.
Tuition fee cap
Aberystwyth University organiser Kieran Ford said: "If the government wants to take university learning away from the masses by making it expensive and out-of-reach to ordinary people then we will take university learning to the masses.
Analysis: BBC Wales education correspondent Ciaran Jenkins
This tells us that the finances of these universities are in a somewhat uncertain state and given that's half the sector in Wales, it's significant.
Universities in Wales already have some problems - a deficit of around £70m, an annual funding gap with England of £65m and last week they were dealt a £50m cut to their budget by the assembly government, so some changes are necessary to keep them going in the long term.
The assembly government hasn't set out its plans yet and I understand it will do so before Christmas, but given that all the universities want the fees to go up and given that they've had this budget cut, a rise in fees does seem inevitable, purely as a way of raising funds.
"It is important that people do not think this is simply a student protest. It affects the wider community."
Katie Dalton, president of students' union NUS Wales, said they were not organising Wednesday's protests but were encouraging students to write to MPs urging them to vote against an increase in fees.
HEFCW chief executive Prof Philip Gummett said the higher education sector faced "challenging financial times for the next few years".
It is the first time the financial sustainability of universities has been measured in this way.
The information about the financial future of Welsh universities was revealed in risk reviews conducted in May and was obtained under the Freedom of Information Act by BBC Wales.
It comes a week after university funding was cut by 12% over three years in the assembly government's draft budget.
Dr Peter Noyes, vice chancellor of the University of Wales, Newport, said all universities in Wales were lobbying Education Minister Leighton Andrew for an increase in student tuition fees.
"It's the only way we can afford to support future cohorts of students to generate wealth in the economy," he said.
"We've said that we will work with him to make sure that system is fair and appropriate for the needs of the Welsh economy."
A spokesperson for Higher Education Wales, which represents higher education institutions, said Welsh institutions were "financially well run and there is no indication that any Welsh university is at risk".
But the spokesperson added that following "significant cuts in public funding" there was "now a need to address the level of graduate contribution in Wales in order to ensure parity of investment with universities elsewhere."