Female joggers beware in No. Calif. city

(CBS/AP) LIVERMORE, Calif. -- Pants on the ground is nothing to laugh at for women in Livermore, Calif. 

Police in the east San Francisco Bay community suspect the same man has been pulling down the pants of numerous lone female joggers over the past several years.

Sgt. Paul Mayer tells the Contra Costa Times that six cases have been reported since 2007, the latest late last month. Most have occurred in the same residential area.

The women, who ranged in age from 19 to 43, were not physically injured or sexually assaulted, and the incidents don't appear to have been filmed, the station said.

Mayer says all the women were wearing sweatpants or shorts and headphones. The suspect's description has varied, but police are investigating the case as if the same person is behind the incidents.

Police urge women to run in pairs or groups, carry a cell phone and vary their routes.