Pop superstar Justin Bieber said he was only human after he snapped and lashed out at a photographer, rounding off a "rough week".
The 19-year-old Canadian singer's latest upset came just hours after a health scare forced him to leave the stage. He burst out of a vehicle and lunged at the photographer, but was restrained by minders in an incident which was captured by a film cameraman.
Bieber explained in a series of messages on Twitter shortly after the outburst - in which he shouted obscenities on a London street - that his adrenaline was running high and that he "let the paps get the best of me".
He had been hustled into a vehicle by his team after leaving his central London hotel, but he leapt from the van, making threatening comments. "What did you say? What did you say?" he shouted, before swearing as his minders dragged him back into the vehicle.
The footage has been posted on the Channel 5 News website, and comes after a week which has seen the singer castigated for letting down his school-age fans, then be treated by medics after apparently struggling for breath on stage.
Writing on Twitter shortly after the incident, he wrote: "Sometimes when people are shoving cameras in your face all day and yelling the worst thing possible at you - well, I'm human. Rough week.
"Not gonna let them get the best of me again. Gonna get focused on this show tonight. Adrenaline is high now. Gonna put it on the stage. Only way someone can break you is if you let them," he added.
Charles Murray, a cameraman for 5 News, witnessed the incident and said it was "an angry outburst". He went on: "He deliberately went out of his way to shove the photographer. The photographer shouted back at him as Bieber got into his car. Bieber then decided to get back out of the car and slapped his camera out of the way."
Bieber is due to perform another show at the O2 Arena, in a week he would probably prefer to forget. On Thursday he quit the stage mid-song complaining of shortness of breath and was checked over by medics.
It came just days after he angered and disappointed thousands of people by starting his first of four nights at London's O2 arena so late that many had to miss most of the show.