Four teenagers were jailed for between five and 20 years for their role in the fatal beating of a 15-year-old boy by a gang armed with metal pipes last year. The Court of First Instance heard the frenzied attack on Wu Yu-hei arose from a dispute over computer games. The attack took place in an open area at Lotus Towers in Ngau Tau Kok on August 26. Wong Tat-sze, 18, Chan Chun-ming, 16, Chan Chi-fung, 17, Man Ka-tat, 18, and a fifth man Chu Yiu-keung, 19, were convicted of killing Wu on January 21. They had all pleaded not guilty to a charge of murder. Man, who had only helped the other assailants locate the victim, was found guilty of a lesser charge of manslaughter. All the others were convicted of murder. Chu, who was aged 18 at the time of the offence, was sentenced to life imprisonment by Mrs Justice Verina Bokhary immediately after the jury returned the verdict. The four men who were below 18 were sentenced yesterday. Mrs Justice Bokhary pointed out it was her discretion not to give them life sentences. Wong was jailed 20 years, the heaviest sentence of the four, with the judge noting he had actually attacked the victim with a metal pipe. There was no evidence, however, that suggested he had delivered the fatal blow. Chan Chun-ming was jailed for 18 years. He was seen holding a metal pipe although he did not actually attack the victim. Chan Chi-fung was jailed for 16 years. He was not armed with a weapon and did not physically assault the victim. Man was jailed for five years on one count of manslaughter. Sentencing the four, Mrs Justice Bokhary said, 'Each of you played a role to participate in a joint enterprise of a vengeful attack on the victim.' She said the defendants could have expected a more severe term if they had been the masterminds of the crime. The trial heard that Wu was attacked by more than 10 men armed with pipes on the evening of August 26 when he was playing cards with friends. He sustained multiple head injuries during the attack and was later certified dead at Queen Elizabeth Hospital from skull fractures. The attack was ordered by teen Billy Lai Kin-bong, who fled the city and is still at large, while another attacker, Ng Ka-lok, also disappeared after the killing. The court heard the pair had triad backgrounds. Wu had previously had a row with Lai because Lai had allegedly once turned off the computer game that Wu was playing at a game centre. The prosecution relied on the accounts of witnesses - three of whom were granted immunity from prosecution - police statements from several defendants and CCTV footage.