About 50 protesters gathered at the university's Australian Institute of Bio-engineering and Nanotechnology, where the prime minister was touring earlier today.
Police formed a barrier outside the entrance to the building where protesters were chanting "lock up Scomo" while carrying signs and tomatoes.
It is understood the Morrison was escorted out through a loading bay, shortly after the building went into lockdown.
Red paint was thrown against the glass doors and windows of the building at both entrances.