Police are growing concerned for a teenage girl who has gone missing with her two-year-old sister.

Clair Smith, 13, left her grandfather's home with her sister Rebecca on yesterday (Tuesday) evening saying she was going to visit her uncle at Darlington's Memorial Hospital.

But she never arrived at the hospital after leaving her grandad's home in St Andrews Street in the town at 6.15pm - and her whereabouts is a mystery.

Clair has been known to go missing before to visit her mother in Plymouth and to Redcar and London - but she has never taken her sister.

Police are concerned for the toddler's well being as she suffers from asthma.

Clair is described as being 5ft 9ins with blue hair and blonde hair. She was wearing a white top with yellow amd black stripes across the front, jeans and a three-quarter length grey coat.

Rebecca was wearing a denim jacket with a pink pattern, jeans, and trainers with flashing lights.

Police are appealing for Clair or anyone with information to get in touch.