An 18-year-old Ghanaian, Frederick Moody, has been stabbed to death after being ambushed by a gang wielding knives in South London.Frederick was stabbed to death last Thursday, six hours after a London court pronounced a life sentence on a Nigerian resident in the UK for the murder of another Ghanaian last year.According to a report in the Daily Graphic, witnesses claimed they had heard the killers shout "leave him for dead" before fleeing the scene in Guildford Road, Stockwell, on bicycles. A 16-year-old boy was arrested yesterday morning in Brixton over the killing.Frederick stumbled down the road before collapsing from stomach wounds in front of his younger sister, witnesses said.Frederick’s death also brings to three, the number of Ghanaians who have died in knife crimes in London within a period of one and half years.The youngster had just left his home when he was attacked shortly after 7.00 p.m. Residents, including a local general practitioner, tried to treat him before paramedics arrived. He was declared dead at 10.15 p.m.The teenager was said to have earlier on grabbed a bag and left the house telling his mother he would be back in a few minutes. But half an hour later when the doorbell rang she answered the door to find no one was there. When the bell rang a second time, it was a neighbour saying her son had been stabbed.Below, read the BBC’s account of the incident