The suicide bomber who brought carnage to the Manchester Arena has been named as Salman Abedi.

Monday night's attack at a concert by US pop star Ariana Grande left 22 people dead, including an eight-year-old girl, and dozens injured.

Abedi, believed to have been born in Manchester and of Libyan descent, studied business at Salford University but dropped out before completing his degree.

The 22-year-old is thought to have attended the Manchester Islamic Centre, also known as Didsbury Mosque, along with his parents and siblings.

A family friend, who asked not to be named, described him as "normal" and said they were known to the Libyan community in the city.

He told the Press Association: "He was always friendly, nothing to suggest (he was violent). He was normal, to be honest."

Abedi was named after armed officers carried out a raid on the red brick semi in south Manchester where he was registered as living.

Greater Manchester Chief Constable Ian Hopkins said detectives were working to establish whether he was working alone or as part of a network.

Residents were ordered to stay inside as around 20 police swooped on a house in Elsmore Road in Fallowfield carrying out a controlled explosion on the front door.

Elsewhere in south Manchester, the first arrest was made in connection with the inquiry when a 23-year-old man was detained near a Morrisons in Chorlton.

As counter-terrorism agencies mounted a massive inquiry into the outrage - the worst terrorist attack since 52 innocent people were killed in the July 7 bombings in London in 2005:

:: The first victims were confirmed as eight-year-old Saffie Rose Roussos from Leyland and teenager Georgina Callander from nearby Chorley

:: Prime Minister Theresa May denounced the "appalling sickening cowardice" of the suicide bomber

:: Many of the 59 people hurt in the attack were treated for life-threatening injuries. Twelve of those rushed to hospital were children

:: Donald Trump denounced those responsible for the atrocity as "evil losers" and pledged America's "absolute solidarity" with the people of the UK

:: Andrew Parker, the Director General of MI5, condemned the "disgusting attack" and declared that the agency remains "relentlessly focused" on tackling the "scourge of terrorism"

The Islamic State terror group claimed responsibility for the barbaric attack, which involved a home-made device packed with nuts and bolts which exploded in the venue's foyer as thousands of young people were leaving.

Mrs May said the perpetrator had chosen the time and place of his attack deliberately to cause "maximum carnage and to kill and injure indiscriminately".

She flew to Manchester to speak to police chiefs and medics treating some of the child victims.

Crowds of people gathered in the city centre on Tuesday evening, standing together in an act of solidarity and spilling from Albert Square onto nearby roads.

The death of Saffie Rose Roussos, the youngest known victim of the attack, was described by her headteacher as "heartbreaking".

Chris Upton, of Tarleton Community Primary School, said: "Saffie was simply a beautiful little girl in every aspect of the word."

Another victim was named by her college as Georgina Callander, who was studying health and social care at Runshaw College in Leyland, Lancashire.

Tributes were also paid to 26-year-old John Atkinson from Bury, who was named by friends on Facebook as an apparent victim.

Meanwhile, fears were growing for Chloe Rutherford, 17, and Liam Curry, 19, a couple from South Shields, 15-year-old Olivia Campbell from Manchester, Eilidh MacLeod, from Barra in Scotland, Kelly Brewster from Sheffield, and Martyn Hett and Wendy Fawell.

All were believed to have been at the concert and have not been traced since the attack.

A rough sleeper who rushed to help victims at the scene said there were "nuts and bolts all over the floor" and people with "holes in their back".

Chris Parker added: "I saw a little girl ... she had no legs. I wrapped her in one of the merchandise T-shirts."

The 33-year-old, who has slept rough in the city for about a year, said he also tended a woman in her 60s with serious leg and head injuries who "passed away in my arms".