Justin Bieber reportedly canceled his Tueday night show in Portugal due to low ticket sales.

"Due to unforeseen circumstances, Justin Bieber was forced to cancel the second operation, in Portugal, on 12 March," posted music promoters Everything is New on their website. "The Canadian singer is eager to play for the Portuguese fans on 11 March."

The site also promised to refund those who had purchased tickets for the concert. "Holders of tickets valid for March 12 should contact the respective place of purchase to receive a refund within 30 days of the date of the scheduled concert, which ends April 11."

Huffington Post cites that, while the first date was sold out, ticket sales had been suspended for the second night due to insufficient demand.

Bieber is having quite a difficult week in the UK. He arrived two hours late for Monday's concert, collapsed on stage this past Thursday, and got into a verbal altercation with a paparazzo Friday.

"i never have any intent to upset or let anyone down. and Im not okay with things being exaggerated. once again sorry for anyone upset." tweeted Bieber last Tuesday.

Justin Bieber's O2 world tour will be transitioning into the Believe tour through the United States starting July.