Detectives investigating the disappearance of 15-year-old Maddie Thomas are now treating the case as child abduction.
Officers believe Maddie is with a man, and she has been missing from the Southmead area of Bristol since Tuesday 26 April.
Detective Inspector Laura Miller said: “We are no longer investigating Maddie’s disappearance as a missing person case but as a child abduction.
“When Maddie has previously gone missing she has been found in the company of adult men and it is mainly due to this history that we believe she is likely to currently be with someone.
The case of Maddie Thomas is now being treated as child abduction.
Image: Avon and Somerset Police
“Maddie is a child in foster care, no one has permission to keep her from her carers. She is vulnerable and at risk of being taken advantage of.
“We’re really concerned about her safety and have a dedicated team working extremely hard to locate her.”
DI Miller added: “No one has seen or heard from Maddie for 15 days – since she saw a relative on 26 April when she said she was going to the shop.
“The circumstances of her disappearance are deeply worrying for us; her family and her carers.
“We have a number of lines of enquiry and while we’ve had great deal of help from the public to date for which we’re incredibly grateful, we still need more.
“Officers have carried out CCTV enquiries in the Southmead area where Maddie was last seen and posters have also been handed out to local residents by officers going house to house.
“But Maddie could be anywhere in the country and so we really need our appeal to be shared and reported on as widely as possible.
“We’re asking anyone who sees Maddie to call 999 immediately and anyone who speaks to her or sees her online to call 101.
“Maddie – if you see this please contact us if you can to let us know you’re safe. Everyone is worried about you.”
Anyone who is able to help is urged to contact Crimestoppers 100 per cent anonymously on 0800 555 111 or via their Anonymous Online Form.