Three teenage bullies who subjected a woman with learning difficulties to a terrifying ordeal in a flat have been locked up by a judge.

The 25-year-old victim, who was described as a vulnerable woman, was punched and hit with various items including part of a vacuum cleaner before being bound and gagged.

Prosecutor John Topham told Bradford Crown Court yesterday that the woman was then forced into an airing cupboard were she was left tied up for five hours before being released.

The court heard that the teenage girls then left the woman locked inside the first-floor flat in Festival Avenue, Shipley, for two more days until police received an anonymous tip-off and forced their way in. "The police saw that she was in a very distressed and unkempt state," said Mr Topham.

The woman was taken to hospital where she was treated for cuts to her head and nose. She had also suffered bruising to her eyes, arms and body, and there was a 20cm-long scratch on her back.

Mr Topham said the woman had been homeless at the time she met up with 16-year-old Yasmin Ali and her boyfriend in July. Ali agreed to let her stay at her flat in Festival Avenue and the woman told police that at first everything was fine, but then things turned nasty and she was kept in the property against her will.

She described how she was assaulted by Ali and her co-accused 17-year-old Sahira Mahmood and 18-year-old Kirsty Fletcher.

Scarves were used to gag her mouth and tie her arms and wrists before a washing line was used to bind her legs.

"She was then locked in the airing cupboard," said Mr Topham. "Once in there they managed to tie her wrist to some kind of hook and rope or something was used to keep the door closed."

The three girls were arrested the day after the woman was released from her three-day ordeal. Last month they pleaded guilty to offences of false imprisonment and assault.

Yesterday Ali, who had previous convictions for Assault, robbery and criminal damage, was sentenced to 18 months in a secure unit.

She will also be subject to an extended period of licence following her release.

Mahmood, of Planetrees Road, Bradford, was locked up for 12 months and Fletcher, of Berrydale Road, Nelson, was sentenced to four months in custody.

Ali accepted punching the woman, tearing off her skirt and putting a scarf round her mouth. During the assault Mahmood had hit their victim with an extension pipe from a vacuum cleaner and also a plug from an iron.

The court heard that Fletcher had intervened to take implements off her co-accused during the assault, but she accepted punching the woman and helping to get the washing line.

Judge Robert Bartfield told the trio they knew their victim was a vulnerable woman with learning difficulties.

"For this kind of conduct there can only be a custodial sentence for it is far too serious a matter for any other form of disposal by the court," he said.

But Judge Bartfield told the girls that after reading reports about them it was clear they all had the potential to lead positive and productive lives.