Sgt. Peter Thiessen said Tuesday that the attacks may date back to April, with incidents following in May, then September and three in October.
The most recent attack was reported to police on Sunday.
"A young woman indicated that she was walking alone. . . shortly before 1:30 in the morning when she noticed a shadow behind her," Thiessen said. "She was grabbed from behind and she began to flail her arms, causing the suspect to run away."
"In all situations, the women were assaulted while walking around the campus late into the evening or into the early-morning hours."
The attacks have spread fear on campus, especially with three of them on consecutive weekends this month.
In the incident on Oct. 19, the man grabbed the woman from behind, ripping her nylons, punching her in the face and giving her a black eye.
It represented an escalation in violence and prompted the RCMP's Major Crimes Unit to take over the investigation.
In all cases, the suspect is described as a Caucasian male with an olive or tanned skin tone. He is in his mid 20s to early 30s with dark hair, a thin build and about six feet tall, Thiessen said.
Police and school officials have been working with campus security and student housing to discuss the use of more lighting and video cameras and a boost to the hours of the university's free Safewalk program, which provides escorts to people walking alone on campus between the hours of 8 p.m. and 4 a.m.
A brochure with safety tips has also been placed in the lobbies of student residences and counselling services for students have been increased.
"We want the attacks to stop," said Louise Cowin, vice-president of students on campus. "We want these crimes solved.
"This is a stressful time for many people on our campus and in this area of the city. This latest news will add to the anxiety. That fear is understandable but it is also critical to act and act decisively."
Thiessen said police have added more resources to the manhunt, and are also working with the Vancouver Police Department.
On the case is the RCMP bike patrol, the dog squad, forensic artists and teams specializing in behavioural science, criminal and geographic profiles and crime analysis.
But Thiessen also renewed the plea for women to watch out for themselves when walking alone on the campus in the evening.
"These attacks seem to be crimes of opportunity, where the suspect is specifically targeting lone females in somewhat secluded areas," he noted.
"We want the public to enhance their own personal safety by minimizing or eliminating those opportunities for this assailant to be able to victimize anyone else in our community."
Thiessen urged women to walk in pairs or groups, be aware of their surroundings, take routes that are well lit along pedestrian or vehicle traffic, to let friends know when they are arriving and what route they are taking.
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