SAN LEANDRO -- Authorities intensified their efforts Tuesday to locate a 19-year-old woman -- reported missing over the weekend -- who is considered at risk because she has a developmental disability.

Stephanie Mathews was last seen around 1:40 a.m. Sunday in the parking lot of the Union Jack Pub at Mission and E. Lewelling boulevards in the San Lorenzo area of unincorporated Alameda County, according to the Alameda County Sheriff's Department.

Staff members from the Emma Lynn Ady Home, a residential facility for developmentally disabled adults, reported Mathews as missing.

She was last seen getting into a blue 2002 Chrysler Sebring with four or five black males. The car bears the California license plate 4VAJ479.

Mathews is described as a white female, 5 foot 5 inches tall, 150 to 160 pounds, with red hair. She was last seen wearing a black shirt, blue denim skirt and stretch pants with silver shoes.

Anyone with information about this case is asked to contact the 24-hour dispatch number of the Alameda County Sheriff at (510) 667-7721, Sgt. Tom Madigan at (510) 667-3667, Detective Lauren Tucker at (510) 667-4907 or the anonymous tip line at (510) 667-3622.