One Direction star Louis Tomlinson has tweeted his thanks to fans for their support after the shock departure of bandmate Zayn Malik.
As the remaining four members vowed to carry on with the global phenomenon that is 1D, Tomlinson said they would work "harder than ever" on their planned fifth album, making it the "best ever".
Been a crazy couple of days but know that we are going to work harder than ever to deliver the best album we've ever made for you guys !
Your support has been incredible , truly incredible so thank you so much !
Fellow former X-Factor boyband members have tweeted messages of support for Zayn Malik tonight after the One Direction star made the decision to quit the band.
Aston Merrygold, of JLS fame, and Union J's Josh Cuthbert both tweeted the star the "best of luck" following the announcement of his departure:
Counselling service ChildLine have warned that young people may be feeling "very distressed" after hearing the news that Zayn Malik has left boyband One Direction, and urged adults not to "undermine" these feelings.
Sue Minto, head of ChildLine, said: "There are young people who are going to feel seriously distressed at the news, and people are going to have to get their head around the fact that for some this will be very distressing and not to undermine it, even if they don't quite understand it."
She added: "Lots of people have pop stars or celebrities or actors who they hold in high esteem, and there is a lot of sadness and impact for people when something happens to any of them."
Anyone who is feeling distressed can contact ChildLine by calling 0800 11 11 or visit www.childline.org.uk.
Former X Factor judge Gary Barlow and McFly drummer Harry Judd have tweeted messages of support to the remaining members of One Direction, departing band member Zayn Malik, and the band's fans tonight.
The stars tweeted:
Bum out news for 1D fans ? Sad to see Zayn go but you gotta do what you gotta do. Brave decision
Malik, 22, first shot to fame after appearing on the X Factor in 2010, now five years after joining One Direction he is quitting the band.Read the full story ›
Simon Cowell, one of the X Factor judges who helped put together boyband One Direction, has said he is "truly sorry" to see bandmate Zayn Malik leave.
In a statement posted on the band's official Facebook page Cowell wrote:
"I would like to say thank you to Zayn for everything he has done for One Direction.
"Since I first met Zayn in 2010, I have grown very, very fond - and immensely proud - of him. I have seen him grow in confidence and I am truly sorry to see him leave.
"As for One Direction, fans can rest assured that Niall, Liam, Harry and Louis are hugely excited about the future of the band."
My life with One Direction has been more than I could ever have imagined. But, after five years, I feel like it is now the right time for me to leave the band. I'd like to apologise to the fans if I've let anyone down, but I have to do what feels right in my heart.
I am leaving because I want to be a normal 22-year-old who is able to relax and have some private time out of the spotlight. I know I have four friends for life in Louis, Liam, Harry and Niall. I know they will continue to be the best band in the world.
Bradford-born singer Zayn Malik has left One Direction. Fans of the band have been tweeting their reaction.
@zaynmalik im not gunna say I won't miss you but im glad that you're putting yourself first. :) it's not gunna be the same without you.
One Direction have posted a statement on their official Facebook page today, confirming the departure of band mate Zayn Malik.
The statement said that "after five incredible years Zayn Malik has decided to leave" but that the other four members would continue as a band without him.
"We're really sad to see Zayn go, but we totally respect his decision and send him all our love for the future.
"The past five years have been beyond amazing, we've gone through so much together, so we will always be friends.
"The four of us will now continue. We're looking forward to recording the new album and seeing all the fans on the next stage of the world tour."
Zayn has left One Direction according to a statement on the band's Facebook page.
Sorry, this content isn't available on your device.
This week the 22-year-old left the band's current tour due to stress.