The Islamic State group yesterday claimed responsibility for a suicide bombing at a packed Manchester pop concert, killing at least 22 people including an eight-year-old girl in Britain's deadliest terror attack for more than a decade.

Police named a young man -- reportedly British-born of Libyan descent -- as the suspect behind the bombing.

Manchester police identified the suspect as 22-year-old Salman Abedi, but declined to give any further details. British media said he was born in the northwestern English city and that his Libyan parents had fled the regime of dictator Gaddafi.

UK Prime Minister Theresa May vowed "terrorists will not prevail", after IS claimed responsibility for the attack at the conclusion of US pop star Ariana Grande's concert late Monday at the Manchester Arena, one of Europe's largest indoor venues.

Campaigning for the June 8 general election, which May called last month to strengthen her hand in forthcoming Brexit negotiations with the European Union, has been suspended.

US President Donald Trump led condolences from political leaders across the globe, as well as stars from the world of music and football such as former Manchester United player David Beckham.

Threatening more attacks, IS said in a statement published on its social media channels: "One of the caliphate's soldiers placed bombs among the crowds."

Manchester police chief constable Ian Hopkins told reporters: "The priority remains to establish whether he was acting alone or as part of a network."

Witnesses described the horror when the suicide bomber blew himself up and anguished parents appealed for information on their loved ones, as Mancunians opened their doors to shelter people lost in the confusion, and taxi drivers offered free rides.

"There were fathers carrying their little girls in tears. People were pushing down the stairs. It was just... chaos," Sebastian Diaz, a 19-year-old from Newcastle, told AFP.

Britain's worst terror bloodshed for more than a decade came just over two weeks before the country votes in a general election, and after a series of deadly jihadist attacks across Europe.

Police staged an armed raid on a Manchester address believed to be linked to Abedi, carrying out a controlled explosion to gain entry after arresting a 23-year-old man earlier yesterday in connection with the attack.

"A single terrorist detonated his improvised explosive device near one of the exits of the venue, deliberately choosing the time and place to cause maximum carnage and to kill and injure indiscriminately," May said after an emergency ministerial    meeting.

She said during a visit to Manchester that police would look at the security of such venues, while the government would also review police resources, writes AFP.

But while campaigning for the June 8 election was suspended by the main parties after the attack, she insisted: "The terrorists will not prevail."

People take part in a vigil for the victims of Monday's terror attack on concert goers at Manchester Arena, in Trafalgar Square, London. Photo: Reuters

'BROKEN'

Screaming fans, many of them teenagers, fled the 21,000-capacity Manchester Arena in panic after the explosion at the end of the performance by the 23-year-old Grande, a former child television star who described herself as "broken" by the attack.

Eight-year-old Saffie Rose Roussos and a teenager, Georgina Callander, were among the first of the 22 victims to be confirmed.

Another 59 people were taken to hospital, many with life-threatening conditions.

Police said the blast occurred in the foyer of the arena, a covered area which links the auditorium to Victoria Station, a train and tram hub.

Witnesses reported seeing bodies on the floor after the blast around 10:30pm (2130 GMT) on Monday, and some fans were trampled as panicked crowds tried to flee the venue.

Families were separated, with dozens of young people taken to nearby hotels overnight, and some parents were still desperately searching for their children yesterday.

"I'm just hearing nothing -- her phone's dead," Charlotte Campbell, whose 15-year-old daughter Olivia was at the concert, told BBC radio.

The attack was the deadliest in Britain since July 7, 2005 when four suicide bombers inspired by al-Qaeda attacked London's transport system during rush hour, killing 52 people and wounding 700 more.

It revived memories of the November 2015 attack at the Bataclan concert hall in Paris in which armed men wearing explosive belts stormed in and killed 90 people.

That attack was also claimed by IS, as was one in March by a knifeman at the gates of the British parliament -- although police downplayed that claim.

Other recent attacks in Europe have included vehicles driven into crowds in Berlin and Stockholm, coinciding with an offensive on IS holdouts in Syria and Iraq by US, British and other Western forces.

'ACT OF BARBARITY'

World leaders including Angela Merkel, Donald Trump, Emmanuel Macron and Putin have come together to publicly condemn the Manchester attackers, reports metro.co.uk.

Queen Elizabeth II condemned the Manchester attack as an "act of barbarity" and observed a minute's silence at a Buckingham Palace garden reception.

Trump said during a visit to Bethlehem: "So many young, beautiful, innocent people living and enjoying their lives murdered by evil losers."

Merkel said: “This apparent terrorist attack will only strengthen our determination to keep acting together with our British friends against those who plan and carry out such inhuman deeds.”

Indian Prime Minister Narendra Modi tweeted: “Pained by the attack in Manchester. We strongly condemn it. Our thoughts are with the families of the deceased & prayers with the injured.”

In Japan a government spokesman said: “If this is a terrorist attack, such abhorrent acts of terrorism cannot be justified for any reason, and Japan firmly condemns such an act of terrorism.”

Canadian Prime Minister Justin Trudeau tweeted, as reported by The Independent, “Canadians are shocked by the news of the horrific attack in Manchester tonight. Please keep the victims & their families in your thoughts.”

The Eiffel Tower's lights were to be turned off at midnight yesterday  in homage to the victims, while the Cannes film festival also observed a minute's silence.

Britain's national terror threat level has been "severe", the second-highest of five levels meaning an attack is highly likely, since August 2014, and May said this would remain unchanged, but under review.

In a city famed globally for its musical traditions and football teams, showbusiness stars and teams joined in to express their shock at the carnage.

"We are deeply shocked by last night's terrible events," said Manchester United.

A support centre for people caught up in the attack was set up at the Etihad Stadium, the home of their rivals Manchester City.

Britain's third biggest city was hit in 1996 by a massive car bomb planted at a shopping centre by Irish Republican Army paramilitaries which wounded more than 200 people.