Police are becoming increasingly concerned about the welfare of a 12-year-old girl who has gone missing from home.
Tia Sharp was last seen leaving her grandmother's home in New Addington at around midday on Friday.
She told relatives she was going to the Whitgift Centre in Croydon town centre.
Police believe Tia had a small amount of cash with her, but no travel card and she had left her mobile phone behind because it was charging.
Twitter has been flooded with appeals for information, with family members and celebrities urging the public to help locate the missing 12-year-old.
Jasmine Hart tweeted: "Hey guys I really need your help! My 12 year old niece called Tia Sharp has been missing for over 24 hours.
"She was last seen yesterday in New Addington, Croydon wearing a yellow t-shirt and glasses. She's very smart and old enough to know how to get around and was given money to buy shoes. It is unlikely that she ran away as it is completely out of character which is why this has become so serious. If you see her or know something, call the police immediately. Please help!"
Choreographer and former Strictly Come Dancing judge Arlene Phillips, UK grime singer and ex-So Solid Crew member Lisa Maffia and glamour model Nicola McLean were among those who added their support to the search by re-posting appeals on the social networking site.
Police made an appeal last night for anyone who might have seen Tia since she disappeared to contact them or her family. Detective Chief Inspector Nick Scola, from Scotland Yard's Homicide and Serious Crime Command said: "I was with her family this afternoon and they are clearly very distressed."
He added: "There is no suggestion she left in a hurry at the moment. We understand her Zip (child's Oyster Card for public transport) was lost some time ago, her mobile phone was left at home charging. She just said she was going shopping."
He said Tia was not known to have a boyfriend and there were no signs she was having any trouble at school.
An area of land nearby was cordoned off and searched yesterday after items were found, but it turned out to be a false alarm.
Today detectives hunting for the missing 12 year old are continuing to sift through hours of CCTV footage for a clue to her location. So far they have found no trace of her.
Tia lives with her dad, David, mother, Natalie, and two brothers in Lancaster Avenue, Mitcham. It was not unusual for her to stay at her grandmother's.
More than 20,000 leaflets have been circulated across Croydon over the last two days by volunteers.
Detectives investigating Tia's disappearance are looking into reports of a driver who may have tried to abduct a child the day before.
Sightings have been reported of a man driving a white van bothering children in the New Addington area - where Tia was last seen.
This afternoon, Tia's grandmother made a radio appeal for her to come home.
Christine Sharp told LBC radio: "She's very much loved, very, very much missed. Just contact any of us whatever way she can."