Police and campus security are attempting to break up a student occupation at Glasgow University.
Dozens of students started a sit-in on 1 February at the former Hetherington Research Club over cuts designed to save the institution £20m by 2014.
The university said it had asked police and security to evict protesters who refused to leave the building, as they were endangering redevelopment plans.
Students are believed to be attempting to re-occupy the building.
It is believed that about 10 university security staff and up to 15 police officers were involved in initial attempts to evict up to 20 students.
Strathclyde Police confirmed that the force’s helicopter had been deployed in the operation.
Since the incident started, more students have joined the protest. It is understood a neighbouring building has also been occupied.
A spokesman for the university said: “The university has previously written to the last remaining students occupying the Hetherington Building asking them to bring their protest to a peaceful conclusion.
“Since then, many students have left the occupation. Police and university security are now evicting those students who have not yet vacated the building.
“The university has allowed the students to sustain their protest for some seven weeks. However, their continuing presence in No 13 University Gardens is now jeopardising plans the university has to refurbish the accommodation and to develop it for academic use.”
One postgraduate student told the BBC that security staff attempted to remove protesters from the building on Tuesday morning.
She said police later arrived and had “forced their way into the building”.
The student said she and others were attempting to re-enter the Hetherington.