Four teenagers have been arrested and charged with raping an 18-year-old student at the University of Massachusetts - Amherst.

Emmanuel Bile, Justin King and Adam Licciardi, all 18 years old and Caleb Womack, 17, from Pittsfield are known to the victim. The alleged perpetrators are said to have sexually assaulted the victim in her residential hall in the wee hours of Saturday (Oct. 13). After a weeklong investigation, the suspects were arrested Friday (Oct. 19).

All four are not students of UMass Amherst. Guests are allowed to visit the students only if they are signed by someone they know. While three of them were signed into the residence hall by someone else, it is not clear how the fourth suspect got into the hall as he was not signed in.

The suspects and the alleged victim were believed to have been drinking vodka before the incident took place. The girl was reportedly slipping in and out of consciousness when the attack took place, said a report in New York Daily News.

"The victim was crying and used the word 'no'," New York Daily News quoted Jennifer Suhl, chief of the sexual assault unit for the district attorney's office, as saying.

Meanwhile, university officials announced that they will carry out a review to look into the security measures of the residence hall.

"The safety of our students is paramount. Following the incident, we communicated with security personnel and residence hall staff to reiterate current security procedures. In addition, while campus security measures have generally proved effective in the past, the university will conduct a comprehensive review of security in our residence halls," UMass Amherst Police Chief John Horvath, said in a statement from the university.

"The campus is providing support to the victim and her family through our well-established resources on campus. In addition, we will redouble our efforts to educate all members of our community about protecting their safety," he said.

The suspects have pleaded not guilty and they are being held on $10,000 bail. If they get out on bail, they will have to wear a GPS tracking device.