A balaclava-clad man who 'targeted' a lone 15-year-old girl, hit her over the head with a metal bar and stole her phone before repeatedly striking her while she was on the floor, has been jailed.

The victim was walking home from a friends house in the early hours of the morning in the Beatty Close area of Great Yarmouth when Nathan Arnold, who was wearing dark clothing and a balaclava, came from behind and struck her on the head.

She dropped her mobile phone which was picked up by Arnold as he walked past her before striking her again in the head.

Arnold, 21, repeatedly struck the victim with the metal bar as she lay on the floor screaming and with her hands out to protect herself.

The teenager, who described being 'extremely scared', suffered a broken hand during the incident which happened in early hours of March 16 this year.

Arnold, of HMP Norwich, but previously of Howard Street North, Yarmouth, appeared at Norwich Crown Court yesterday to be sentenced after previously pleading guilty to robbery.

Sentencing the defendant to six years with an extended three year licence period to reflect his dangerousness, Judge Nicholas Coleman described it as a 'targeted, planned robbery'

He said: 'This was an attack on a 15 year old girl on her own on a public place in the early hours of the morning.

'She was vulnerable, you targeted her, it was planned and you were in disguise. You had a weapon, a metal bar.'

Jonathan Morgans, mitigating, said Arnold was 'genuinely remorseful', was visibly upset, and would have to 'live with what he did for the rest of his life and will live with it every day'.