The band just released a statement on their Facebook page:

After five incredible years Zayn Malik has decided to leave One Direction. Niall, Harry, Liam and Louis will continue as a four-piece and look forward to the forthcoming concerts of their world tour and recording their fifth album, due to be released later this year.

Zayn says: “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.”

One Direction say: “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.”

Simon Cowell says: “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.”

Zayn left the tour recently due to stress and anxiety after cheating allegations began spreading online and in the news.