A Harvard undergraduate student walking from the Porter Square MBTA station was pulled into a Somerville alleyway by a man trying to attack her, the most recent of two attacks on women leaving the train station.
Harvard University police issued an advisory about the attack on a student on Tuesday. Later on Wednesday, Somerville police released more information and said that the attack was similar to one that took place near Porter Square last week.
During the most recent attack, the female student was walking on Beacon Street at about 1:20 a.m. Monday near an alley that leads to Oxford Street in Cambridge, according to Harvard police. The woman, who was walking from the Porter Square station,told police that a man grabbed her arm and pulled her into the alley.
"The victim screamed for help and defended herself against her attacker," Harvard police said in their advisory.
She then fled the area.
Somerville police released a sketch of the suspect and said the woman described the attacker as a thin black man in his 30s, about six feet tall and clean shaven. He was wearing dark clothing.
On Wednesday, Somerville police said that they are investigating whether Monday's assault is related to the attack on a woman in Cambridge on April 16. That woman had also left the Porter Square MBTA station just after midnight and was walking alone on Richdale Avenue when a man assaulted her.
"Police will be diligent in their investigative efforts to identify, apprehend, and prosecute the individual who is responsible for this incident," Somerville Police Chief Charles Femino said in a statement. "If anyone has any information or sees anything suspicious, we encourage you to report it immediately to Somerville Police."
Anyone with information can call617-625-1600.
Follow Michael Naughton on Twitter @metrobosmike.