Pop superstar Justin Bieber said he was only human after he snapped and lashed out at a photographer yesterday, 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 photo-grapher, but was restrained by minders in an incident captured by a film cameraman.

Bieber explained in a series of messages on Twitter 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 minders dragged him into the vehicle.

The footage has been posted on the Channel 5 News website.

Writing on Twitter shortly after yesterday’s 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 deliberately went out of his way to shove the photographer. The photographer shouted back at him as Bieber got into his car. Bieber got back out of the car and slapped his camera out of the way.”

The star, idolised by young fans, was heard to shout: “I’ll beat the f*** out of you.”

A record company representative did not comment on the outburst by the teenage singer.

On Thursday night he quit the stage mid-song, complaining of shortness of breath, and was checked over by medics.

Earlier yesterday a representative for the singer said he was feeling “under the weather” after his health scare on-stage, but was still planning to perform.

He had posted a picture of himself online lying in a hospital bed shortly after the show, during which he had to take a break as he struggled to breathe.