A man riding a bike and wearing a ski mask grabbed a woman near Fresh Pond, and the incident could have gone further had the man not fallen off his bicycle, police said.

At about 8 p.m. Tuesday, the woman walking on the path across from 679 Concord Ave. from the Fresh Pond Reservation area was approached by a man on a  black, sport-type – but not a mountain bike – BMX bicycle. “As this male rode past her in the opposite direction, the victim noticed that he was staring at her in a way that made her feel uncomfortable,” Deputy Superintendent Steven DeMarco said in a Cambridge Police press release resulting from the woman’s report.

She walked on but heard the bicyclist turn around, so he was riding at her from behind. He rode up alongside her and touched her indecently – now wearing a black ski mask, DeMarco said.

The victim ran up the path and onto Concord Avenue. “She noticed the male suspect, who had followed her, had fallen off the bicycle,” then got back on and fled away from her, back down the path toward the pond, DeMarco said.

The suspect is described as a white and between the ages of 20 and 25.

Last month two grabbing incidents were reported by women in the Inman Square area, and in each case the man was on a bicycle. But the assaulter was described as a dark-skinned man with dark curly hair around 18 to 25 years old. In each case he wore a bright red or light-colored T-shirt and dark shorts.

Indecent assaults are not addressed in the police department’s most recent Bridgestat crime report, but the report covering all of last year said that of 33 total reports of indecent assault, the majority – 13 incidents – were reported in the quarter including July, August and September. The annual total was down from 41 in 2012.

Of the eight indecent assault arrests last year, five were strangers to the victims such as in the incidents reported in June and Tuesday. (In November, a Revere resident was arrested after three Cambridge assaults that were “part of a regional pattern,” the report says.)

Cambridge Police are investigating the Tuesday crime, and anyone with information is asked to call the Criminal Investigation Section at (617) 349-3370. Anonymous reports can be left at (617) 349-3359; sent by text message to 847411 (begin your text with TIP650, then type your message); or by email by visiting CambridgePolice.org/Tips.

Residents, particularly women who must walk alone at night, are urged by police to stay vigilant and aware of their surroundings; to keep to well-lit routes; make eye contact with those around them; wear sneakers or shoes that allow for added mobility; and avoid wearing headphones or ear buds. A phone should be readily available, but distracting phone calls should be avoided. People who feel they are being followed should show they are suspicious and turn to look at the person to send a clear message they will not be taken by surprise; head for a store or building they know to be open; change directions, either crossing the street and varying your if someone is following by foot or turning and walking in the opposite direction if the person following is in a car.

In addition, police say:

Walk with confidence on the street and at a good, steady pace. Keep your head up and observe your surroundings. Don’t look down at the ground. Don’t let anyone violate your space. Trust your instincts. Anyone at any time can be a victim of crime, so never assume “It will never happen to me.”

Try to remember descriptive information about the suspect (height, age, race, etc.) to relay to police when reporting the incident.

Keep a whistle within reach. If threatened, use the whistle to signal residents for help. Yelling “Fire!” “Help!” or “Rape!” are ways of drawing attention and alerting people of your situation.

Street safety tips are available online here, and Cambridge Police offer a free self-defense class for woman who work or live in the city. The class is taught for four consecutive weeks for three hours each session. Participants must commit to attend all four sessions, as the class is intended to build muscle memory through repetition on basic, hands-on self-defense techniques as well as teach risk-reduction strategies and avoidance measures. The course is free. For information, call (617) 349-3236.

This post took significant amounts of material from a press release.