Thousands of people have gathered in the centre of Manchester in a show of defiance, declaring they will not be afraid in the wake of the terror attack.
Crowds spilled from Albert Square on to nearby roads, standing together in an act of solidarity, and showing that the city "always pulls together".
Senior figures including Home Secretary Amber Rudd, Labour leader Jeremy Corbyn, Liberal Democrat leader Tim Farron and Speaker John Bercow joined Manchester Mayor Andy Burnham on stage before mourners began laying flowers and lighting candles.
The crowd erupted into applause as the vigil began, and Lord Mayor of Manchester Eddy Newman said it was a chance to "express solidarity" with the victims.
He thanked the emergency services, prompting a rapturous response from the emotional crowd.
The square later fell silent as they remembered the lives of those who died.
Greater Manchester Police's Ian Hopkins said: "As your Chief Constable of Greater Manchester and as a father I cannot begin to imagine how anyone can carry out such an unthinkable act - murdering 22 people and injuring 59 - and my thoughts and those of my colleagues are very much with their families at this incredibly difficult time."
Mr Hopkins added: "Last night, in the most atrocious circumstances, the people of Greater Manchester showed the world how much we care.
"How much we care about each other and how much we were prepared to help those in need.
"And I've heard some tremendous stories of doctors coming in to support, and police officers, ambulance workers giving up their days off, turning up to help those in need."
Mr Hopkins thanked those who had worked "tirelessly" through the night, "members of the public for their solidarity" and "the rest of the world for holding us in their thoughts".
"We must all stand together and not let the terrorists defeat us, not let them stop us going about our daily business and create fear, and we must all live in harmony with each other as we stand together and defeat terrorism," he said.
Poet Tony Walsh performed a touching ode to Manchester called This Is The Place, which sparked ripples of laughter, lightening the mood as the sun beamed on the Town Hall.
He described the city as "ace", hailed its "brilliant music" and said Mancunians "make people laugh" and "welcome".
In a poignant moment he referred to the "Mancunian way to survive" and "northern grit", and said: "In the face of a challenge we always stand tall."
Members of the public wept as they laid flowers and lit candles.
Lu Bowen, 40, brought flowers to lay as a mark of respect, and said it has been a "horrific" day.
Standing alongside her teenage daughter Lucy, she said: "We felt we wanted to show a sense of solidarity and commitment that Manchester always has.
"When the chips are down, Manchester always pulls together."
She said some of her friends felt nervous about the prospect of coming into the city on Tuesday night, adding: "I personally just want to make a stand that even if my friends felt a bit nervous, I felt it was very important to prove that I won't be beaten, intimidated.
"And also, people have lost loved ones. If it was me, I'd want to see this."
She added: "It's been a horrific day. But we all feel the same here. We're here together."
Sue Shevlin, 43, and Sinead Ginty, 24, wiped away tears as they turned from the growing pile of floral tributes.
The pair said they had come to "show some respect and support".
Ms Ginty said the city would "stand together as one - Muslims, Christians, atheists".
"We've got to stand together - every religion," she said.
Stephanie Aims was among those in tears and said the attack brought back memories of the 1996 IRA bombing in Manchester.
Ms Aims, who lives in Birmingham but used to live in Manchester, said: "You can't stop doing what you need to do. You have to go on with everything, and you can't be afraid to come and show your respects."
Tom Buchan, from Heywood, came to lay flowers after being moved by the death of eight-year-old Saffie Rose Roussos.
The 29-year-old said he felt he "had to do something", as he left a card with the message: "To Saffie Rose, RIP my darling, we will stand together."
He said: "The eight-year-old girl, that really got me this morning as my little boy is eight."