The grandmother of 14 year-old girl missing in northern Tasmania for more than four days says the family is "sickened with worry".
Shyanne-Lee Tatnell, from Burnie, was last seen in an area near Henry Street in Launceston about 8:30pm on Sunday.
Tasmania Police's Sergeant Hamish Woodgate said she was on her way to visit a friend, but she did not arrive.
The rescue helicopter has been deployed to conduct aerial searches.
Miss Tatnell is 160 centimetres tall, with blonde hair and a slim build.
Her grandmother, Michelle Hubbard, said no one had heard from her since Sunday afternoon.
"There's been no phone contact and no social media, which is very unusual for Shyanne because she's usually on it 24/7."
Ms Hubbard said her granddaughter was polite, affectionate and "not very street savvy".
"She's a lovely, sweet young lady," she said.
"She's very trusting, probably too trusting of people.
"She's had some mental health issues and has been struggling with those."
Ms Hubbard pleaded with her granddaughter that if she was reading the news coverage to give someone a call.
"Please, please Shyanne, please make contact with someone so we know you're safe," she said.
"Then we can get you home to us where you are so needed and so loved."
Public help sought
Miss Tatnell was last seen wearing a cream, hooded jumper with black writing on the front and shoulder.
She had been staying in youth accommodation in Launceston for the past two weeks.
Staff where she was staying alerted police to her disappearance.
Sergeant Woodgate said he would appreciate any information, especially dash-cam vision from vehicles in the area at the time.
"Any information as far as anyone who's seen her in a particular location at a particular time, whether or not she was seen in the company of anyone else," he said.
"Any information along those lines would be of great assistance."