Brother (23) of suicide bomber is arrested in raid by police
The suicide bomber who blew himself up killing 22 people and injuring 119 was named as 22-year-old Manchester-born Salman Abedi.
Islamic State has claimed responsibility for the ballbearing bomb attack at the Ariana Grande concert.
The attack was the worst Britain has seen since the 7/7 London bombings in 2005, when 52 innocent people died.
Police yesterday carried out a controlled explosion at what is believed to be Abedi's home during a series of raids across Manchester.
A former school friend said Abedi, who was known to police, had recently grown a beard and neighbours claimed he had been "acting strangely".
Abedi was born in Manchester on New Year's Eve 1994, the son of a Libyan couple who had fled to Britain to escape the Gaddafi regime.
A 23-year-old man, believed to be Abedi's brother, was yesterday arrested as police and security services attempted to work out whether Abedi was acting alone or as part of a terrorist cell.
Security sources revealed last night that initial analysis of the "sophisticated" bomb suggest it was made by an expert.
Abedi is believed to have travelled to Manchester by train from London, according to US intelligence officers.
Leon Hall, who went to school with Abedi, said he had grown a beard when he saw him last year.
"We didn't speak but just nodded to each other. I don't remember seeing him with a beard before," he said.
Meanwhile, Abedi's neighbours have spoken of his "strange behaviour" in recent weeks, and of how he would "chant Islamic prayers loudly in the street" outside his home in the south of the city.
Abedi, who was a keen Manchester United fan, appears to have been radicalised within the past couple of years.
Greater Manchester Police Chief Constable Ian Hopkins said yesterday: "I can confirm that the man suspected of carrying out [Monday] night's atrocity has been named as 22-year-old Salman Abedi.
"However, he has not yet been formally identified and I wouldn't wish, therefore, to comment further.
"The priority remains to establish whether he was acting alone or as part of a network."
Eight-year-old Saffie Roussos, 18-year-old Georgina Callander and 26-year-old John Atkinson were among those killed.
Twelve children were among the 59 seriously injured people taken to hospital. Another 60 people were treated at the scene.
Traumatised witnesses have told how nuts and bolts tore into the young music fans when the bomb was detonated in the foyer of the Manchester Arena moments after US popstar Grande left the stage.
Abedi lived in a modest red brick semi-detached house in a mixed suburb of Manchester, where police performed the controlled explosion.
Neighbour Natalie Daley said that, prior to the explosion, she heard police yelling, "Get in your houses. Get away from the windows".
"When it's like two seconds from your home, when you walk past it every day, you do live in fear," she said.
Akram Ramadan (49), a married man with an eight-year-old daughter, lived in a flat above one of the properties raided by police.
He said a newlywed couple moved into the property about nine months ago.
He said the husband, a man in his mid-to-late-20s, was a Mancunian of Libyan descent, while his wife was a maths teacher who had helped his own daughter in her studies.