Neighbours say the flat door in Greenwich was smashed open by balaclava-wearing police armed with machine guns.
Officers were heard shouting "get down on the floor". Two women thought to be sisters were handcuffed and led away.
A teenage boy, a toddler and a baby were also taken away.
This video shows the clash between Justin Bieber and photographers outside his London hotel.
Read the transcript of their exchange here.
These pictures show Justin Bieber's scuffle with a photographer outside his London hotel.
Here is a transcript of the scuffle between Justin Bieber and photographers outside the star's London hotel:
Bodyguard: Watch out, give us some space guys.
Photographer: OK, OK.
[Bieber pushes photographer]
Photographer: Easy! Easy! That's assault. That's assault.
Bodyguard: Yeah, but you're in our way. Relax.
Photographer: No, I moved out the way. F-----g little c---. That's assault. F--k back off to America. F-----g little moron.
Bieber: What the f--k did you say? What did you say? I'm gonna f-----g beat the f--k out of you.
Photographer: You heard what I said. Lose your f-----g bouncers.
The singer Justim Bieber has tweeted about his altercation with a photographer as he left a hotel in central London:
Ahhhhh! Rough morning. Trying to feel better for this show tonight but let the paps get the best of me...
From @justinbieber on Twitter:Sometimes when people r shoving cameras in your face all day and yelling the worst thing possible at u...well I'm human. Rough week
From @justinbieber on Twitter:Not gonna let them get the best of me again. Gonna get focused on this show tonight. Adrenaline is high now. Gonna put it on the stage
From @justinbieber on Twitter:Justin Bieber has "clashed" with a cameraman outside his London hotel, Channel 5 news reports.
In the footage, Bieber is seen pushing a member of the press out of the way as he climbs into a waiting car.
He then gets out of car and pushes the cameraman again, shouting a stream of expletives.
EXCLUSIVE VIDEO: Justin Bieber clashes with a cameraman outside his hotel http://t.co/Zncx3IwCBc
From @5_News on Twitter:Watch the video in full on the Channel 5 News at 5pm.
@the_o2 Omg u dnt know how happy I am to c this .
From @kelhurc12 on Twitter:@the_o2 omg so pleased my daughter will be so happy..
From @GinnClare on Twitter:Good mornig everyone. As things stand Justin Bieber is still set to perform the final night of his shows at The O2 this evening.
From @The_O2 on Twitter:@justinbieber LOVE YOU it was amaing even though you went off! You didn't have to apologise!!! We love you!
From @Kardashian4Evax on Twitter:@justinbieber u were amazing,I'm so proud of u for coming back on. I couldn't ask for a better idol, thank you. I love you, get better soon.
From @kidrauhlsfredo on Twitter:@justinbieber I really hope you're okay! It was so sweet of you to finish the concert for the fans. Love you.
From @BieberSupportEU on Twitter:
Pop star Justin Bieber posted picture of himself from his hospital bed and said he was "getting better listening to Janis Joplin".
