Girls caught the constable Shankar Lal, who was standing outside their hostel and passing comments on them yesterday, police said.
Annoyed over the act the students beat up the constable and took him to a nearby hospital for a medical examination, as they suspected that he was drunk.
However, the alcohol test report was negative but Shankar was booked for creating nuisance at a public place, police said.
"We have initiated a departmental inquiry against him," a police officer said.