Justin Bieber has apologised for arriving on stage late for a sell-out UK concert, leaving his fans angry and disappointed.
The singer did not begin his performance at London's O2 Arena last night until 10.30pm - long after many of his school-age fans would normally have been in bed.
Today, the Canadian pop star tweeted: "I was 40 min late to stage. there is no excuse for that and I apologize for anyone we upset. However it was great show and Im proud of that."
Many fans had blasted the 19-year-old singer with messages on Twitter.
Some complained they were stranded after the late finish and a number of others had to miss the gig altogether in order to catch the last train home from London. Father Wayne Parsonage said he ended up missing the show to ensure he could get home, and wrote on Twitter: "Disgusting. Waste of my time and money... never again."
Tracey Wilson, from Hoddesdon in Hertfordshire, took her teenage daughter, who has school today, to the concert. The pair were left stranded after missing their train home and instead had to be collected by her husband.
She told BBC Radio 5 live the support acts overran by around 20 minutes to 8.50pm, finally followed by Bieber an hour and a half later. She said: "There was no apology to say why or 'I'm really sorry' or to say something's happened. It's disgusting.
"It got to about 9.30 and they were starting to boo - you'd think someone would have come on then."
Another tweet complained: "Justin Bieber needs to understand he has fans that are really young. He can't come on stage like 1 hour and 45 mins late on a school night!"
It was the first of Bieber's four nights at the London venue.