SAN ANSELMO (CBS SF) – Police are investigating a suspicious circumstance in which a man in a van offered a ride to a teenage boy on Tuesday afternoon.

The 13-year-old boy was standing in front of a fire station on Butterfield Road near Arroyo Avenue, close to Brookside Elementary School, when the incident occurred around 3:30 p.m.

READ MORE: Big Sur Residents Told to Boil Water Due to Possible Wildfire Damage to Utility

As he walked past the van, which was stopped on the side of the road, the right sliding door and the right front passenger window opened, police said.

The male passenger asked the boy if he needed a ride home, and the boy said “no” and walked away. The woman behind the wheel then drove off, police said.

Police searched the area but did not find the vehicle, described as a newer-model silver van with dark rear windows. The boy said there were no seats in back of the van but that a yellow Labrador-type dog was barking in back, police said.

READ MORE: Hazardous Sneaker Waves Threaten San Francisco Beachcombers

The driver is described as a white woman in her 20s with black hair. The male passenger was a white man in his 20s with long blondish-brown hair. He was wearing a beanie.

Anyone with information about the van and occupants is asked to call San Anselmo police at (415) 258-4610.


MORE NEWS: UPDATE: Air Attack, Calming Winds Aid Firefighters Battling Wildfire Near Big Sur; Containment Grows To 25 Percent

(Copyright 2012 by CBS San Francisco and Bay City News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)