The younger brother of the Manchester Arena bomber is "just as guilty of the murder of 22 people" as his sibling, a court has heard.
On May 22 2017, Hashem Abedi's brother Salman detonated an explosive device as music fans left an Ariana Grande concert, killing 22 people and injuring many more on May 22 2017.
Hashem Abedi, 22, is on trial at the Old Bailey accused of helping him plan the suicide attack.
Opening the case, prosecutor Duncan Penny QC said:
On the evening of Monday 22 May 2017 in the public foyer outside one of the entrances to the Manchester Arena in central Manchester shortly after the conclusion of a concert by the singer Ariana Grande, this defendant's brother detonated a large home-made improvised explosive device - a bomb packed with shrapnel contained in a rucksack on his back.
Mr Penny said Abedi had assisted and encouraged his brother.
Abedi allegedly obtained chemicals for a home made bomb; got metal containers to construct it; found an address in Manchester to manufacture the explosive and store it and bought screws and nails for shrapnel.
In mid-April 2017, he also purchased a Nissan Micra to store bomb-making equipment, the court heard.
Mr Penny said the explosion was the result of month of planning, experimentation and preparation by the brothers.
He said: "The bomb which was detonated was self-evidently designed to kill and maim as many people as possible.
"It was packed with lethal shrapnel and it was detonated in the middle of a crowd in a very public area - the intention being to kill and to inflict maximum damage."
Abedi, originally from Manchester, denies 22 counts of murder, attempted murder and conspiring with his brother to cause explosions.