Five people were assaulted on Tuesday night, including four police officers.
One officer was taken to hospital as a precaution after suffering an injury to his arm while making an arrest.
Three girls, a 17-year-old and two aged 13, and have been bailed.
Fireworks were let off in Clapham High Street and fires lit on Clapham Common.
Shop owners also reported having to barricade themselves in their premises.
It’s thought the incident on Tuesday night, and the previous Saturday, was part of the TikTok “swarm the streets” trend on social media.
A Lambeth Council spokesperson said:
“Council officers and elected representatives are on the scene to provide community support. We will continue to have discussions with the Met police about the situation as the week progresses.
“The council is also working proactively with the police to prevent repeats of these incidents and is using CCTV to support the investigations.
“Our youth outreach team will be supporting young people in the area as part of our community reassurance work.”
