Harry Styles halted a concert in London to call for security staff to help a female fan who suffered a panic attack.

The One Direction star kicked off the U.K. leg of his solo world tour at the Eventim Apollo on Sunday (29Oct17), but had to halt the gig while singing Just a little Bit of Your Heart, the song he wrote for Ariana Grande.

Video posted on Twitter shows Harry, 23, breaking off from the track to look at the fan iand say, "Is everyone okay? You still with me? Do you wanna help her up? If everyone could give her some space. If everyone could chill for one second, we'll get some people."

The fan, who posts on Twitter under the name @alienwhiteside, later confirmed she had received medical attention after suffering a severe panic attack.

"Harry Styles stopped his entire show because I got crushed and then watched me being pulled over the barrier," she wrote. "That was one of the most horrendous panic attack's I've ever had like even the medics were terrified of the state I was in."

She thanked Harry and her fellow concert goers for ensuring she received treatment, adding, "I'm so grateful to harry for having such a pure heart and stopping the show to get security to help me."

The fan wrote that she was "upset" to miss half the show but managed to obtain a ticket to the Sign of the Times singer's show the following night (30October17).

Before the concert, the kind-hearted popstar provided pizza and hot chocolate for gig-goers who queued up for days to obtain a prime spot in the audience.

All One Direction's members had reason to celebrate on Sunday, as Niall Horan's solo album Flicker debuted at the top of the Billboard 200 chart. Harry and Zayn Malik's own solo efforts had already topped the countdown, meaning the group have now matched The Beatles as the only band to have three current or former members who have earned number one albums.