Left-wing groups have accused the government of exploiting the incident to justify the presence of police at universities.
Greek police have raided a university campus in Athens in an operation against suspected drug trafficking and armed robberies.
At least one person was injured, while 32 people were arrested at the National Technical University of Athens, police said.
The suspects are not students but allegedly used old dormitory rooms on the campus to stash weapons, drugs and money.
“They used the campus as a staging ground to carry out robberies and drug trafficking,” said Dimitris Davalos, director of the criminal division of the Greater Athens police department.
One suspect was hospitalised with a gunshot wound after allegedly attacking an arresting female officer, police said.
Police said they had seized firearms, knives, expandable batons and other weapons, along with cocaine, marijuana and drug-processing equipment.
The raid, involving police special forces and members of an antiterrorism unit, took place on Tuesday.
The operation has also reignited controversy over a measure that introduced police officers to university faculties.
For decades, police officers were legally banned from entering campus grounds without permission from academic authorities.
Left-wing opposition groups have accused the Greek government of "exploiting" the raids to justify police presence at university campuses.