Transcript for British authorities are searching for Manchester bomber's potential 'network'

evening, just 22 years old. He just returned to England five days before the attack. So, where was he right before and was his brother about to unleash another bomb? And tonight, what they have just discovered in the suspect's home. Here's ABC's Brian Ross. Reporter: Tonight, these pictures on the front page of the British tabloids of Salman Abedi, as a British schoolboy. And a goofy-looking teenager at the beach. No indication of his rapid road to jihad. But tonight, we are learning he had been recruited by ISIS, and that five weeks before the attack he traveled to Libya, an ISIS stronghold and his family's ancestral home, returning on may 17th, to Manchester -- just five days before he set off his bomb. Officials in Libya today say they have arrested the bomber's father, who in this interview before the arrest said he son was no terrorist. Authorities also arrested the bomber's younger brother Hashim, who authorities say confessed he was in the process of what they called his own act of terrorism and knew exactly how his brother's bomb was made. ISIS has posted videos online showing how to build a variety of suicide bombs. But experts say the details in the Manchester bomb show greater sophistication, including a design like the one used by ISIS for bombs in Paris and Brussels, and more than one detonator. Really suggesting that he probably did not act alone, that he probably had some help, that he certainly had some advice on how to create the bomb. Of course, that was the concern all along. Brian Ross with us. Brian is just getting information in about what inves gators have now found in the suspect's home. It was described to me as kind of a bomb workshop. Unused chemicals more than enough for several more bombs. Brian Ross and your team. Thanks to you

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