Justin Bieber celebrated his 21st birthday again with wild party in Las Vegas on Saturday (14.03.15).

Justin Bieber

Justin Bieber

The 'Baby' singer hit the big milestone two weeks ago but is keen to drag out the celebrations for as long as possible and was in his element over the weekend when he marked the occasion with a swarm of screaming girls at the Omnia Nightclub.

The hunky star was given a large car-shaped birthday cake, which Omnia had designed specifically for him, and he even treated fans to a performance on stage before dancing the night away.

The 'Boyfriend' hitmaker performed 'Wait For A Minute' - his new single with rapper Tyga - and then went on to sing, ironically, a rendition of 'Happy Birthday To You' to himself.

Justin appeared in good spirits considering he'd just come from the taping of his Comedy Central Roast, where funnymen and women came together to make a dig at his criminal record, his bizarre hair styles and his young fan base.

Kevin Hart joked: "Bieber has 10 million fans - most are in middle schools, or standing at least 500 feet away from one."

Snoop Dogg added: "Justin, you're so pretty, when inmates see your mug shot, they swipe right."

However, despite the nasty comments, the hunk appeared to take it all in his stride and enjoyed the evening.

Taking to Twitter afterwards, he wrote: "Tonight was one of the best nights ever. Thank you to everyone involved. Thank you"

The 'Roast of Justin Bieber' will hit TV screens on March 30 in the US and March 31 in the UK.