Two men and three teenagers have been arrested on suspicion of the attempted murder of activist Sasha Johnson, police say.
Officers detained three teenagers and two older men on suspicion of other offences, before they were all also arrested on suspicion of attempted murder.
The first suspect, a 17-year-old boy, was held on Tuesday afternoon, accused of suspicion of possession of an offensive weapon and drug dealing.
Police then raided an address in Peckham, where they arrested three men – aged 18, 19 and 28 – on suspicion of affray and possession with intent to supply class B drugs.
A fifth man, aged 25, was arrested later that evening following a car chase, on suspicion of affray and failing to stop for police.
Ms Johnson was one of the organisers of the first-ever Million People March last August to protest against systemic racism in the UK. During the demonstration, hundreds of people took to the streets of west London.
She is also one of the leaders of the Taking The Initiative Party (TTIP), a political party that was registered with the Electoral Commission nearly four years ago and fielded its first candidates in May’s local elections.
Detective Chief Inspector Richard Leonard said the investigation into the incident on Sunday was in its "early stages", but progress was being made.
He added: "I continue to appeal to those who may hold information about the events that led to Sasha receiving her horrific injuries, or about those responsible, to do the right thing and come forward and speak to police."
Ms Johnson, who graduated from college in Oxford and has two children, was at a party in the back garden of a home in Consort Road when four men in dark clothing burst in and shots were fired.
A man aged in his 20s suffered a "superficial" knife injury as the violence erupted, but he was not seriously hurt.
Anyone with information should contact police on 101, tweet @MetCC quoting the reference CAD1172/23MAY, or call Crimestoppers anonymously on 0800 555 111.