At least 12 people were arrested by police after a large group of protesters staged a demonstration outside the Houses of Parliament over plans to criminalise squatting.
Around 150 people gathered in Parliament Square in Westminster shortly after midnight in the pre-planned demonstration, according to reports.
BBC Radio 5 Live said a number of scuffles broke out between police and protesters, with officers using batons and loud hailers in an attempt to disperse the crowds.
The majority of protesters moved away from the scene peacefully, but around 50 people refused to leave claiming they were holding a Halloween picnic, it was reported.
They were held within a police cordon and a number were arrested before the area was cleared by around 3am, eyewitnesses said.
Scotland Yard confirmed that 12 arrests have been made in connection with the incident, but said the number could rise.
Politicians are due to debate The Legal Aid, Sentencing and Punishment of Offenders Bill later today which proposes that squatting is made a criminal offence.
Under section 132 of the Serious Organised Crime and Police Act (Socpa) - (April 2005), organising or participating in an "unauthorised" demonstration within 1km of Parliament is a criminal offence.