India, June 28 -- A security guard from the south Kolkata law college in Kasba, where a 24-year-old student was allegedly gang-raped on Wednesday evening, was arrested on Saturday.

Two students - Zaib Ahmed (19) and Pramit Mukherjee (20) - and a staffer of the government-run law college, Monojit Mishra (31), were arrested on Thursday.

"We have arrested a security guard of the college. This is the fourth arrest in connection with the case. The probe is ongoing," a senior officer said.

Police said the alleged incident took place between 7.30 pm and 10.50 pm on Wednesday, when the woman had gone to the college to fill out some forms for an upcoming exam. The woman - who was allegedly the TMCP's women's wing secretary in the college - was ...