MANCHESTER, United Kingdom - US pop star Ariana Grande announced on Tuesday she would return to Manchester to headline a star-studded benefit concert for the victims of the deadly attack on her show last week.

Justin Bieber, Coldplay, Katy Perry, Miley Cyrus, Pharrell Williams, Usher and Take That will join her for Sunday's concert in memory of the 22 people who died, seven of them children.

"Our response to this violence must be to come closer together, to help each other, to love more, to sing louder and to live more kindly and generously than we did before," Grande said.

The 23-year-old said she was "broken" and suspended her world tour after the bomb went off near an exit of the Manchester Arena at the finale of her show on May 22.

Fans who attended that show will be offered free tickets to the benefit concert at the Old Trafford cricket ground, which has a 50,000 capacity for concerts, with the rest sold to raise money for the affected families.

Grande is a favorite of preteens and as well as the children killed, a number of the victims were parents who came to pick up their daughters.

Manchester-born Oasis frontman Liam Gallagher made his solo debut on Tuesday with a sell-out concert in aid of the bombing victims.

Like Grande's, it raised money for the We Love Manchester Emergency Fund set up by the local council and the British Red Cross, to help the grieving families and victims.

Ahead of the show starting, 25-year-old Marnie Taylor said she hoped Gallagher would boost everyone's mood.

"Kind of bring back the gig spirit of what gigs are supposed to be, they're supposed to be safe, they're supposed to be somewhere where people can escape," she told AFP outside the O2 Ritz venue.

Gallagher said it was important to move forward in the wake of the terror attack.

"We need to enjoy life... We'll be trying to lift people. Otherwise the poor kids who died at the gig have died in vain," he told the Manchester Evening News.

As life in Britain's third-largest city resumed a semblance of normality, the train station next to the attack site reopened earlier on Tuesday.

"There's still a weird feeling, you know, armed police, a lot of unease," said 59-year-old David Keys as he got off a train at Manchester Victoria.

Troops were deployed at key public sites last week as the country's national terror threat was raised to maximum, and police hunted suspected accomplices of bomber Salman Abedi.

The 22-year-old, who was born in Manchester to Libyan parents, was killed in the attack, which was claimed by the Islamic State group.

The threat level was reduced back from "critical" to "severe" on Saturday, and the army has been stood down.

Xinhua - Afp