Justin Bieber worries fans after viral video of him hugging, shaking girl surfaces

Justin Bieber has sparked concerns about his health, after a bizarre video of him greeting fans surfaced online.

The clip, branded "disturbing" by his followers, sees the pop star, 24, twitching and shaking as he takes photos with admirers on the street.

The "Baby" hitmaker first appears to be poking fun at his fans' excitement in the video, before he starts to twitch uncontrollably with his eyes closed.

Drawing a fan in for a hug, Justin is then seen frantically stroking her back, before he turns to the camera for a picture with his fists shaking in front of him.

The video immediately went viral online, with fans voicing their concerns he had taken drugs on Twitter.

One wrote. "Oh my god, one of the worst things I saw this month - This is year is the vid going around of Justin Bieber tweaking hard. It’s so disturbing I wished I never watched it."

As others agreed, "I hate how Justin Bieber looks now.. it’s so disturbing cause I’m such a huge fan!"

"Yoooo. Justin Bieber is hella tweaking now," another said.  "There's a video going viral of him all tweaked on on the streets, meeting fans. So f----g sad dude."

And finally, "I’m sorry for such a stretch but he looks like he has a drug problem and instead of anyone addressing it y’all all laughing at his appearance....The video comes two years after Justin vowed to not take photos with fans in public, as it made him feel "drained, unhappy, and mentally exhausted."

This story originally appeared in The Sun.