A missing 12-year-old Tacoma, Wash., girl is not a runaway, and authorities fear she was abducted, police said Friday.

The girl, Zina Linnik, disappeared near her home while watching fireworks on the Fourth of July. A witness heard a girl scream and saw a gray van driving away.

"My father heard the scream and by the time he got out of the house, just saw the driver running around to the front of the car and sped off," the victim's brother, Stan Linnik, told local KTVB KING 5 News.

Zina is 4 feet 10 inches tall, 80 pounds and was wearing a pink T-shirt, capri pants and flip-flop sandals.

Of Ukrainian descent, Linnik is also described as blonde, with her hair pulled back in a ponytail at the time she vanished.

Police are looking for a gray van with a license containing the numbers 1677. The driver may be an Asian man.

"The family has no reason to think anyone would take the girl," Mark Fulghum of the Tacoma Police Department told KING 5 News. "She's not a runaway risk."

Police urge any witnesses with helpful information to call 911 immediately.

The Associated Press contributed to this report.