POLICE are seeking witnesses to a crash in which a public bus hit a nine-year-old boy just after school yesterday.

The youngster had to be airflifted to Bristol's Frenchay Hospital following the incident on Westfield Way, near Asda Walmart, at around 3.17pm while the road was closed for five hours for specialist police to carry out an examination of the scene.

The bus driver and passengers on the Thamesdown Transport bus were unharmed but the boy, who is not from the local area, was left with life-threatening head injuries.

Dr Leon Roberts, the on-board doctor with the Great Western Air Ambulance, based at Filton airfield, said the boy was assessed at the scene by Wiltshire Aire Ambulance, who then called for specialist back-up.

He said: "Initially the lad seemed quite stable but he soon deteriorated and the Wiltshire Air Ambulance, the first helicopter to arrive, assessed him as requiring treatment at Frenchay.

"We were on standby at Filton airfiled with the Great Western Air Ambulance, which is equipped with a doctor and a paramedic and we can administer anaesthetic.

"He had very serious injuries and underwent a head scan at Frenchay."

PC Chris Penny, of the Serious Collision Investigation Team, said: "At around 3.17pm on Friday there was a single vehilce  serious injury collision on Westfield Way approaching Haydon roundabout.

"A single-decker bus driven by a local man was travelling along Westfield Way when a nine-year-old child, not from the local area, ran out into the road in front of the bus.

"He was seriously hurt in the collision and needed to be airlifted to Frencahy Hospital. The bus driver and passengers were unhurt.

"The Serious Collision Investigation Team attended the scene to conduct an investigation into the circumstances. The road was closed or five hours while the scene was cleared.

"We would like to hear from anyone who witnessed the incident and they should call SCIT at Devizes Police Headquarters."

Anyone with any information should contact PC Penny on 101 extension 720 3110 or Crimestoppers anonymously on 0800 555 111.