Police are urging women not to walk alone at night on the University of British Columbia campus in Vancouver after two women were groped.

Early Thursday, a man grabbed a woman who was walking alone on Biological Sciences Road, then fled the area. The woman was not injured.

RCMP Sgt. Peter Thiessen said the incident is similar to another groping that happened on campus in September.

"There is just some general similarities in the type of area that it occurred and some general descriptions that may be somewhat similar," he said.

"But there are some differences as well, so we are not clear on whether they are linked or not but felt it necessary to put the information out."

In the earlier incident, a woman told police she had been walking along University Boulevard just after midnight when an unidentified man approached and tried to grope her. The woman was able to break away but was not able to provide a detailed description of the man, police said.

In light of the two incidents, Thiessen urged women on the campus to be cautious.

"We're encouraging women on the UBC campus to be vigilant, to carry cellphones and to avoid walking alone, especially at night," he said.

The man in Thursday's incident is described as Caucasian, between 30 and 35 years old and about five feet eleven inches tall, with dark hair and eyes. He was wearing dark blue jeans, a dark windbreaker and a dark baseball cap.

Anyone with information is asked to contact the UBC RCMP detachment at 604-224-1322 or Crime Stoppers at 1-800-222-8477.

Police seek Burnaby witnesses

Meanwhile, Mounties in Burnaby, B.C., are looking for witnesses to a sexual assault that took place early Friday.

Police say a 19-year-old woman was walking along a path near the SkyTrain line, at Edmonds Street and Griffiths Drive, just before 1 a.m. when she was approached by a man on a bicycle.

The man exposed himself and asked for sexual favours. When she refused, the man assaulted her and fled on the bike. The victim suffered minor injuries, police said.

The assailant is described as Caucasian, 28 to 32 years old, about five feet eight inches tall and 150 pounds, with a medium build. He had short, curly brown hair and a beard. He was wearing a black T-shirt and light-coloured sweatpants and was riding a red bicycle.

Anyone with information is asked to call the Burnaby RCMP at 604-294-7794.