One Love benefit concert in Manchester

Singer Ariana Grande returned to the stage in Manchester on Sunday with a program packed with upbeat, defiant pop songs. "Manchester, we're gonna be all right," she yelled, as she kicked off the One Love tribute concert, aimed to raise money for those affected by the May 22 bombing.

Long queues stretched outside the Old Trafford cricket ground where the charity gig was held. A host of stars performed alongside Ariana Grande, including Justin Bieber, Katy Perry, Coldplay, Take That and Miley Cyrus. Former Oasis frontman Liam Gallagher - possibly Manchester's most famous rock star - also made a surprise appearance.

British singer Robbie Williams also took to the stage, changing some of his lyrics of "Strong" to honor the Manchester victims. "Manchester we're strong ... we're still singing our song," he sang with the more than 50,000 people estimated to have attended the event.

An armed policeman poses for a photo with music fans ahead of the concert. There had been fears the event might be canceled after the terror attacks in London on Saturday night. But Grande's manager, Scooter Braun, said the Manchester concert would go ahead "with greater purpose" because of what happened in London.

An armed policeman stands at the entrance of the Old Trafford cricket ground. Police had warned security would be tight at the event, with "significant" numbers of personnel and mounted officers.

The concert's overwhelming message was one of unity and defiance in the face of terror. The concert was streamed worldwide on television and the internet, with all proceeds going to an emergency fund set up by the city of Manchester and the British Red Cross.