The Clearlake Police Department is investigating the disappearance of two 15-year-old girls missing since Nov. 17.

Police do not know whether they are runaways or the victims of foul play. In any case, detectives are concerned about the girls because of their age.

"It's not typical for girls to be gone for a week," said Clearlake Police Det. Ryan Peterson. "They're 15 years old so they are vulnerable where ever they are."

The girls, who are best friends, are Sara Beck of Clearlake, 5 feet 7 inches tall, 135 pounds with blonde hair and hazel eyes; and Lacy Elwood of Clearlake Oaks, 5 feet 6 inches tall, 145 pounds, with blonde hair and blue eyes.

They were reported missing from their homes last Saturday. Police said the girls were last known to be headed to a Taco Bell and then over to a friend's house.

Police said there have been several unsubstantiated reports about the girls' whereabouts. In one report, the girls were seen near a local hotel or may be headed to the Ukiah area. Another report suggests that the girls may have cut and dyed their hair dark.

Police asked that anyone with information about the girls call the Clearlake Police Department at 707-994-8251.

The girls' parents are "frantic" and want to know that their daughters are safe, police said.

Police also said that anyone who may be harboring the girls and does not report their whereabouts to investigators could be prosecuted for contributing to the delinquency of a minor.