Justin Bieber walks shirtless back to his tour bus in Frankfurt

Justin Bieber ditched his top and was seen walking back to his tour bus with his shirt slung over his shoulder in Frankfurt on Thursday.

The thermometer was struggling to get above zero in the city but the singer didn’t seem to mind the freezing temperatures.

Justin Bieber, 19, had his jeans riding low and his white underwear was left on show, as he strolled to the coach.

The teen idol has been spotted shirtless on a number of occasions in recent weeks, including during his turbulent stay in London and as he made his way through security in Poland just last week.

Justin Bieber may well be feeling invincible after a number of schools changed their timetables because of his Believe tour.

Five schools in Norway swapped their exam dates to ensure students can attend Justin Bieber’s concerts at the Telenor arena later this month, according to reports.

Kristin Halvorsen, Norway’s education minister told Associated Press: “I am concerned that students should be concentrating when they take tests and midterms. The local schools have the responsibility to schedule the local midterms, and if they think there is any reason to change the dates, they have authority to do so. We’ve all been 14 years old and know that interests can be intense.”