Agitated over the incident, students gheroed the residence of the University Vice Chancellor.
VC Prof D P Singh has assured the students that strict action will be taken against the culprits.
The victim -- Sonia was coming out of BHU health centre with her friend Santosh Chandravesh this afternoon when Shailendra Shekhar, a former student of the university and Gulab Singh abused her and later even physically assaulted her, officials said.
Sonia and Santosh received head injuries, they said.
Gulab Singh has been arrested while Shailendra is absconding, they said.