Bieber apologizes for late UK show

There was no on-stage apology, although the O2 Arena did later address fans, popularly known as "Beliebers", apologizing in a Twitter message to "all the Justin Bieber fans for the lateness of his show tonight".

Bieber is due to play the same venue on Tuesday, Thursday and Friday.

Many people voiced their frustration at having to wait, while others reacted angrily to the headlines.

"Justin Bieber is my fave person but 2 hours late on stage is a joke!" fan Jess wrote on Twitter. "Does he realize that he has fans under the age of 10?"

Others jumped to his defense early on Tuesday.

"Feel really bad for @justinbieber now! Yes he was late but he put on a flipping good show! It was amazing," said one.

Not all reviewers were quite so kind for the singer who was named by Forbes magazine in 2012 as the third most powerful celebrity in the world.

London's Evening Standard awarded the "Baby" singer two stars, saying he turned "victory into defeat".

"By the end, the O2 was barely half-full and when Bieber asked 'Who's seen me play before?', he might have been better wondering who would spend time, money and adoration on seeing him again," wrote critic John Aizlewood.

Bieber's visit to Britain has probably not been his best.

On March 2, the day after he turned 19, he tweeted "worst birthday" amid reports some of his entourage were turned away from a London nightclub because they could not supply adequate proof of their age.

Bieber, who was discovered on YouTube in 2008, last month became the youngest artist to land five chart-topping albums in the United States following the release of his latest record, "Believe Acoustic".