The assault occurred about 1pm on Saturday in Goulburn Street, just north of George Town fire station.

The woman on the footpath told the teenager to "get into the car", which was being driven by a man, her suspected accomplice.

The girl, who was physically unharmed, fled and raised the alarm with relatives who called police immediately.

Police have appealed for more information about the movements of the sedan - a white, mid-1990s model, four-door Hyundai Excel.

Inspector John King, of Northern Criminal Investigation Branch, said the two people were not known to the girl.

"This is a disturbing incident which we are treating very seriously," he said.

Inspector King said parents should encourage their children to walk with someone else or in a group, where possible.

"And as this teenager did, contact police to report suspicious activity as soon as possible."

Inspector King urged anyone with information relating to the vehicle or the man and woman involved to call police on 131 444 or Crime Stoppers on 1800 333 000.

Neighbourhood Watch Tasmania chairman Jan Dunsby encouraged parents and guardians to talk to their children and young people about stranger awareness.

Ms Dunsby suggested self-protection strategies including:

● Walk away from the roadside to avoid being easily grabbed by someone in a car.

● Turn your body away if someone confronts you.

● Remember a person's distinctive features to help with identification.

● Stay on known streets when on foot.

● Avoid talking to strangers, even to give directions.

● Never divulge personal details, including your name and address.

● Avoid strange cars.

● Never accept gifts, lollies or any other item from a stranger.

● Keep a safe distance away from strangers to avoid them grabbing you.