A judge has admitted she slipped up when she sentenced three young men to a total of 31 years behind bars over a violent shotgun incident in Blackburn.

Amjad Niwaz, 25, Mohammed Imtiaz Malik, 25, both from Blackburn, and Anjum Nawaz, 24, from Sheffield, were all sentenced by Mrs Justice Rafferty at Manchester Crown Court in May after they admitted having a firearm with intent to endanger life.

Niwaz, of Grindleston Road, was given a 13-year jail term; Nawaz, of Columbia Place, Sheffield, received 10 years and Malik, of Montague Street, got eight years.

However, at London's High Court, Mrs Justice Rafferty said she had made an error in not giving the trio credit for their guilty pleas. Niwaz's sentence was slashed to 10 years, Nawaz had his reduced to eight years and Malik's was cut to six years.

The trio were prosecuted over an incident in the early hours of the morning of June 18, 2007, when two gunshots were fired through the windows of a house on Whalley New Road.

A 20-year-old student was woken by a disturbance outside his home and, as he went to investigate, two shots were fired at the house, which narrowly missed his head and showered him and his 13-year-old brother with glass.

Both brothers left were shaken by the ordeal and police inquiries revealed the family living at the address were not the intended targets.

The shots had been intended for two men living next door.

The attack was said by prosecutors to be the culm-ination of a dispute between two rival groups of Asian men.

After passing sentence on May 19, Mrs Justice Rafferty had 28 days in which to amend the sentence passed on the trio under what is known as 'the slip rule'.

Had that deadline passed, their only recourse would have been to challenge their sentences in the Court of Appeal.

At a brief hearing in London, the judge accepted she had misinterpreted sentencing guideline cases on May 19 and had failed to give the three credit for their guilty pleas.

She exercised her power under the slip rule to amend the sentences.