FREMONT -- A 15-year-old girl who has the mental capacity of a child and disappeared from her home Thursday afternoon was later spotted trying to catch a ride to Modesto, police said Friday.

Kristina Krage walked away from her home on the 38800 of Bonnie Way in the Glenmoor district about 4 p.m. Thursday, said Detective Bill Veteran. She was last seen by high school classmates around 8 p.m. Thursday outside Bronco Billy's Pizza Parlor at 37651 Niles Blvd., authorities said. She has not been seen since.

The teenager has the mental capacity of a 7 or 8 year old. Kristina also has a significant speech impediment, police said.

A teen who saw Kristina trying to catch a ride to Modesto -- where the teen's mother is thought to be homeless in that city -- called police Friday after learning of the disappearance. The girl's father, Chris Krage, said his daughter has slipped away before, but does not usually stay out over night.

Police have contacted Modesto police and the Stanislaus County Sheriff's office, as well as other police agencies between Fremont and Modesto.

Kristina is Caucasian, 5 foot 4 inches tall and about 160 pounds, with brown hair worn in a ponytail. She was last seen wearing a pink T-shirt, bluejeans and black tennis shoes.

Anyone with information should call Fremont police at 510-790-6800.

Contact Erin Ivie at 925-847-2122. Follow her at Twitter.com/erin_ivie. Contract Kristin J. Bender at kbender@bayareanewsgroup.com. Follow her at Twitter.com/kjbender.