A Mottingham chicken shop owner whose business was terrorised by a group of youths tried to stand up to them but was stabbed by one of the teens.

The 17-year-old attacker, who cannot be named for legal reasons, has now been given a restraining order banning him from Favorite Chicken and Ribs, along with a 10-month detention and training order.

Bromley Magistrates' Court was shown CCTV footage of the group of hooded youths "causing a disturbance" inside the Kimmeridge Road shop before the manager turfed them out on January 7 this year.

The group left, but the court heard on March 17 how the 17-year-old spat: "Who are you? F*** off you idiot."

Footage then showed a confrontation outside between the pair before the teen appeared to draw a knife and lunge at the shopkeeper with it.

The court was told how the victim was stabbed in his leg, leaving his trousers soaked in blood before the group left, some driving away on motor scooters. He required three stitches but was back at work again the next day.

In mitigation, the teen's lawyer Caroline Downs said her client had been acting in self-defence, using the blade of a "multi-tool" which he carried on him because he felt a "general fear".

She claimed the manager had threatened her client, telling him: "Don't come back in this f***ing shop."

Speaking in court, the boy, clad in a black Nike top with blue stripes, said: "I'm sorry for what happened. It was a one-off, it was a mistake."

Asked what he was thinking when he produced the knife, he shook his head and replied: "I don't know."

At an earlier hearing, the teen had admitted possession of an offensive weapon and GBH without intent.

Sentencing him, magistrate Jenny Mole said: "These offences are very serious. You took a knife into a public place and you stabbed someone with it. We have to think about protection of the public when reaching a sentence like this."

As the boy's mum broke up in tears, his grandfather stood up and pleaded: "I'd just like to apologise to the gentleman, the victim and his family, on behalf of my family."