The search for missing schoolgirl Kayleigh Haywood is now being treated as a murder inquiry, police have said.
The news came as officers widened the search to include an area of agricultural land 10 miles away from her home.
Kayleigh, 15, has not been seen since being dropped off in Ibstock, Leicestershire, on Friday.
Detective Chief Superintendent David Sandall, Head of Crime at Leicestershire Police, said: "We have become increasingly concerned for Kayleigh's safety as the hours have passed since she was dropped off by her dad on Friday evening.
"Five days on, we've heard nothing from her and this is completely out of character.
"Since we started looking for her we have found her mobile phone in Melbourne Road, Ibstock and items of clothing which we believe are hers in the Ibstock and Diseworth areas.
"In all the circumstances, we fear the worst and have told her family to prepare themselves that we are now treating her disappearance as a murder inquiry.
"We have searched several locations including Sence Valley Forest Park in the Ibstock area looking for her. This is a considerable expanse of land.
"The park has been cordoned off and is likely to remain so for some days yet while we conduct a thorough search of the area looking for her.
"A number of other locations are currently being searched, including an area in Belton and Diseworth.
"We have a number of active lines of inquiry but we would urge the public to continue calling the dedicated incident room if they have any information which could assist us.
"Were you in the Diseworth or Belton areas between Saturday afternoon and Monday morning, did you see anyone or any vehicles acting suspiciously?
"If you can help please call 0800 096 1233 or 0207 158 0197.
"I am grateful for the help and support provided by the public and partner agencies involved in this investigation."
Kayleigh's parents, Stephanie Haywood and Martin Whitby, have also appealed for anyone with information about their daughter's whereabouts to contact the police.
Meanwhile, officers are continuing to question two men - aged 27 and 28 - who were arrested in the early hours of Monday in connection with the inquiry.