Members of a teenage gang - one as young as 14 - have been sentenced for their parts in a terrifying playground attack in which a student was stabbed and a pitbull was set loose in the school building.

The gang entered the school and let the pitbull off the leash before confronting a pupil.

The 16-year-old victim was knifed six times, and suffered a punctured lung, after he intervened in the dispute.

He was only saved by police community support officers who were patrolling the area, stemmed the pupil’s blood flow and contacted police who arrested six of the group on site.

The incident happened at a Wandsworth school - which can’t be named - on April 24 this year, at about 3.15pm just as pupils were leaving for the day.

At the trial the court heard how the 14-year-old swung a metal dog chain during the attack and how other gang members - who were not part of those being sentenced - chanted a gang slogan after the attack.

The gang were sentenced at Inner London Crown Court on Friday, after all of them pleaded guilty at an earlier hearing.

Sentencing, Judge Diana Faber said the six gang members were part of a larger group of boys that had trespassed into the school.

She said none of the gang had been proven to be carrying a knife, and said that she was taking into account time already spent in custody when sentencing.

“Boys, staff and police community support officers all became involved and the action took place in the school ground and school premises,” she said, “CCTV shows pupils running away from the scene.”

Robert Anderson, 18, of Streatham - who had served four months in custody - received a six month supervision order and was ordered to serve 40 hours community service after pleading guilty to violent disorder.

The 14-year-old and a 16-year-old, who had both been in custody since April, pleaded guilty to the same charge and received supervision orders - three years and one year respectively.

Another boy, also 16, was bound over for the year.

Shadrick Heslop, 18, of Stockwell, pleaded guilty to fear and provocation of violence, and was sentenced at an earlier hearing to 18 months, which included time for other offences.

Another 16-year-old, admitted the same charge and was given a conditional discharge.

The stab victim has since recovered.