Thousands of people have taken to social media sites to help in the search for missing girl Tia Sharp, last seen on Friday afternoon.

Police renewed their appeal on Sunday for help in finding the 12-year-old who was last seen leaving her grandmothers home in The Lindens, New Addington at midday.

The school girl, who lives in Pollards Hill, Merton, told her family she was going to the Whitgift Centre, Croydon to buy shoes. She has no phone, having left her mother’s mobile, which she borrowed, at her grandmas.

Her father David Niles called on anyone who may have seen her to help.

He said: “Our family is heartbroken. We are at our wits’ end.”

Since her disappearance a Facebook group has been set up to spread the word, attracting more than 2,500 followers, and Twitter has been inundated with calls to find her.

Tia was wearing a yellow top, grey faded leggings and trainers, she is 4ft five inches and was wearing designer sun glasses.

Police are examining CCTV footage but have been unable to locate her.

Volunteers from New Addington have been scouring the area and hundreds of missing person posters have been placed around the town.

DCI Nick Scola of the Specialist Crime and Investigations Unit, said there had been a number of reported sightings of Tia but none had been confirmed as being her.

He said: “We are currently examining CCTV and at this time have found no trace of Tia, but this is an ongoing process which will take some time. “We are particularly keen to hear from anybody in The Lindens area who may have seen Tia after midday on Friday.

“We know Tia was using her mum’s mobile phone as hers is broken, but she left it at her grandmother’s house.

“We understand she had a small amount of cash with her which we believe to be around £10. “As we head into a third night of searching for Tia I reiterate our appeals for anyone who may have seen her or has information about her to come forward.

“She didn’t have her zip card and I appeal for bus or tram drivers in Croydon area who recognise Tia’s description to contact us.”

Anyone who has seen Tia or knows of her whereabouts should call the incident room on 0208 721 4005 or Missing People on 116 000.