A 20-year-old college student has alleged gang rape at a friend’s birthday party, where she was invited on Friday.

The young woman, who also does a part-time job, has alleged that she was invited to a birthday party where two men, she knew from before, raped her, police said. She managed to flee their captivity on Saturday morning and filed a complaint with the Haridevpur police station on Saturday.

Police have started a case. No arrests were made till late on Sunday. Both the accused men, including a government employee, were missing, the police said. A medical test of the victim was conducted on Saturday, police said.

According to the complaint lodged with the police, one of the woman’s friends took her to another friend’s home in the Regent Park area on Friday night, around 10.45pm, to celebrate the latter’s birthday.

“However, she was gang raped inside the house. Preliminary investigations have revealed that the act of offence was preplanned,” said an officer of Haridevpur police station.

A police team took the woman to the house in Regent Park on Saturday night to gather details about the incident. The owner of the house where the alleged incident happened was missing.

The police said the accused had rented the apartment.

Police sources said the investigators would submit a prayer before the court to record the woman’s statement before the magistrate.

“We are investigating the complaint and verifying the victim’s statement in detail,” said a senior police officer of Kolkata Police.

The accused have been charged under sections of gang rape, stalking, causing grievous hurt and wrongful confinement.

The charges could lead to a maximum punishment of life imprisonment.

More than two months ago, a law college student had lodged a complaint of gang rape against a former student and two students of the South Calcutta Law College, based on which police had arrested the three accused and later rounded up the security guard for his alleged role in facilitating the crime.

Another incident of rape was reported against a student of the Indian Institute of Management Calcutta. The woman had alleged that she was raped in the hostel inside the institute campus. However, later, the woman did not get her statement recorded before the magistrate, weakening the case.

The accused student has been granted bail.