Justin Bieber Celebrates His Birthday Shirtless, Parties Until 6 A.M.: Pictures

USMagazine, Friday, March 1, 2013, 6:30am (PST)

Justin Bieber in his birthday suit -- or, at least, half of it! After performing a show as part of his Believe tour in Birmingham, England on Thursday, Feb. 28, the "Boyfriend" singer celebrated his 19th birthday by partying into the the wee hours of Friday morning.

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"Great show! Now gonna go celebrate 19! Thanks," the birthday boy tweeted to his fans about his last show as an 18 year old.

After the concert, Bieber headed back to his London hotel to change . . . and got a head start on his way there. The teen heartthrob arrived shirtless, with his blue leather pants pulled down past his white underwear. Bieber showed off some of the 12 tattoos that he has and his six-pack abs while stopping briefly to pose for pictures with fans.

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After changing in his hotel, Bieber was ready for a night out on the town. The "Somebody to Love" singer headed back out wearing baggy, black leather pants, a black shirt, tan sweater, hat and shades.

According to the Daily Mail, Bieber partied with friends, including British singer Ella-Paige Roberts Clarke, at the members-only after-hours club BLC until 5 a.m. The birthday boy and his pals then headed to London's Edgware Road for some late night snacks before calling it a "night" at 6 a.m.

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Bieber -- who recently split with Selena Gomez -- was tweeting reminders to his fans all week that his birthday was coming up. "My birthday is on friday," he tweeted Tuesday with a smiley face.

This article originally appeared on Usmagazine.com: Justin Bieber Celebrates His Birthday Shirtless, Parties Until 6 A.M.: Pictures