SAN DIEGO -- Authorities warned the public Tuesday about a nearly yearlong series of gropings and indecent exposure crimes targeting female pedestrians in the University City area.

Since last May, a dozen women and one teenage girl have reported being grabbed and/or "flashed" by a man in his early to mid-20s in the area of Regents Road and Arriba Street, and at the nearby University of California San Diego campus.

In each case, the crimes have played out quickly, after which the assailant runs off, SDPD Capt. Shelley Zimmerman said.

"We're talking seconds," she said.

Police initially publicized the assault spree last December. A new "rash" of similar crimes in recent weeks prompted the follow-up public alert, according to Zimmerman.

The attacks, three of which occurred on the UCSD campus, have taken place at various times of the morning, afternoon and nighttime, she said.

All of the victims have described the perpetrator as a thin, clean- shaven Hispanic or Middle Eastern man with short, dark hair. In each case, he was wearing dark-colored pants and a hooded jacket with the hood up.

Police advise female pedestrians to protect themselves from such crimes by walking and exercising in groups, paying close attention to their surroundings at all times, carrying cell phones, parking in well-lighted areas and promptly reporting any suspicious-looking people or occurrences.