The brother of a bomber who carried out a suicide attack on the Ariana Grande concert in the English city of Manchester three years ago was announced guilty too, prosecutors told Londons Old Bailey court on Tuesday. Salman Abedi, a British born to Libyan parents, blew himself up at Manchester Arena at the close of a show by the Grammy-winning US pop singer killing 22 victims, including seven children. The youngest aged just eight. The attacked injured at least 500 people. On Tuesday, his brother Hashem Abedi, 22, went on trial accused of helping his brother to carry out the bombing. However, he denies any involvement in the attack. "Hashem Abedi is just as responsible for this atrocity and for the offences which are identified in the indictment ... just as surely as if he had selected the target and detonated the bomb himself," prosecutor Duncan Penny said. Penny said Hashem Abedi helped his brother to get the ingredients for making the the homemade bomb and together they experimented with its construction, buying items such as screws and nails to be used as shrapnel. "This explosion was the culmination of months of planning, experimentation and preparation by the two of them," Penny noted, Reuters reported. "The bomb which was detonated was self-evidently designed to kill and to maim as many people as possible." Hashem Abedi was extradited to Britain from Libya in July last year after the Libyan authorities agreed to hand him over. ISIS said it was responsible for the attack in the immediate aftermath of the bombing, but security services have always treated that claim with scepticism. In 2018, British lawmakers concluded that the MI5 security service had missed potential opportunities to prevent the bombing.