TWO drunken 15-year old girls who robbed and beat a frail 17-year old as she made her way home at night have had their sentences substantially reduced on appeal.

The two Blackburn girls - who were named only as 'S' and 'D' for legal reasons - carried out "an appalling act of street violence" on their victim, beating and kicking her during a ten-minute ordeal, before making off with her mobile phone.

They pleaded guilty to robbery at Preston Crown Court, and were each sentenced to three years detention on May 12 this year.

But one girl's sentence was halved and other girl's was reduced to two years by Mr Justice Richards, sitting at London's Criminal Appeal Court.

The court heard how the pair had been drinking on the night of January 23, when they stalked and attacked the 17-year-old girl who was walking toward Blackburn centre.

They dragged the girl, who was only 4' 10" tall, to the ground by her hair and repeatedly kicked and punched her in the stomach and head before she eventually escaped by fleeing into a nearby block of flats and screaming for help.

The Crown Court judge had described the attack as, "a callous, cruel incident of bullying which had been fuelled by drink", and Mr Justice Richards, sitting with Mr Justice Bean agreed with that description.

However, he decided that the sentences were too long.

"In our view the judge was entirely justified in taking a serious view of this type of robbery, involving as it did the sustained use of violence against a much smaller victim by two drunken girls," he said.

"But, having regard to their early pleas of guilty, their age and, in the case of 'D', her previous good character, a shorter disposal was open to the court," he concluded.

The judge then substituted detention and training orders for the original sentences of straight detention, effectively cutting 'D''s sentence in half to 18 months and reducing 'S''s by a year.