The sister of Salman Abedi claims her brother acted out of revenge against “Muslim children dying everywhere”, 9 News reported.
Jomana Abedi said the 22-year-old called his mother moments before detonating a nail bomb in the foyer of Manchester Arena following an Ariana Grande concert, killing 22 people and injuring scores more.
In an interview with the Wall Street Journal, Ms Abedi said she believes her brother was motivated by injustice in Syria.
“I think he saw children—Muslim children—dying everywhere, and wanted revenge. He saw the explosives America drops on children in Syria, and he wanted revenge,” she said.
“Whether he got that is between him and God.”
CCTV images have been released which show Abedi buying a backpack at the Arndale Centre before the deadly bombing and walking through the Manchester Arena.
It comes as British authorities work to uncover the “network” behind the deadly attack, with six men in custody in England and Libya with fears a second attack may be imminent.
Authorities believe Abedi had help in building the bomb, which photographs published by the New York Times showed was sophisticated and powerful, and that his accomplices could be ready to strike again.
After the attack Manchester police raided a number of properties across northern and central England arresting five men and one woman on Wednesday, but the woman was later released without charge, Manchester Police said.
Manchester Police also confirmed two more men were arrested this morning (local time) bringing the total number of people in custody to eight.