© TwitterPeople partying in Leicester Square and right, playing cricket in Peckham.
Footage shared on social media shows a large group of young people dancing and singing as a sound system blares music in Piccadilly Circus.
Most of the people filmed were not wearing masks and social distancing measures put in place by the Government were not being followed.
The video appeared to have been recorded at 10.37pm on Saturday night.
In another video taken in Peckham, a large crowd took to the streets and people were filmed playing an impromptu game of cricket in the middle of the road.
James Jones, a documentary maker who caught the game on video, told PA: "My guess was that it had recently started as everyone was kicked out of the local pubs and bars.
"I was there for about 10 minutes and it was still going strong."
Mr Jones, himself from Peckham, said that the game felt like a "moment of joy".
"Obviously on social media people are projecting all sorts of views onto it.
"Being there, it felt like a very sweet and exuberant moment of joy. And we could all do with some more joy at the moment!"
Crowds have been gathering in Rye Lane in Peckham for several weeks after the street was closed by Southwark Council as part of a package of coronavirus measures. Residents have complained of a rise in anti-social behaviour.
Other videos showed packed tube trains "similar to rush hour" and crowds lining the streets, dancing and drinking.
The government is expected to announce a new 'three tier' set of covid restrictions on Monday aimed at curbing a second wave of the virus. The restrictions will apply to London as well as cities in the north of England.
Yesterday similar scenes were filmed in Leicester Square in London.
Footage taken on Friday night showed groups of men and women dancing in the middle of the square.
Leicester Square crowd dispersed by police
London Mayor Sadiq Khan posted on Twitter today: "We live in a time when the simple act of wearing a mask could save countless lives.
"Think about that for a moment. The choices we make every day have serious consequences in the real world.
"Be a hero. Wear a mask.
On Friday afternoon Mr Khan told LBC that tighter restrictions for London were 'inevitable' next week.
The Mayor warned the virus is "accelerating in every part of London."
The latest ONS figures show coronavirus is spreading fastest among teenagers and people in their early 20s.
I've never seen cricket. (Though we do have large, loud ones down here.)
R.C.