Four people, including a pensioner, have been taken to hospital after shots were fired from a vehicle in south London.
The victims all suffered gunshot wounds following the "indiscriminate" shooting in Brixton early on Saturday.
A 25-year-old man is in a life-threatening condition, while three others, aged 21, 47, and 70, had non-life-threatening injuries.
The Metropolitan Police said it was investigating whether the stabbing of a man nearby about an hour later was linked to the shooting.
Officers were called at 1.14am on Saturday to reports of shots fired from a vehicle in Coldharbour Lane, Brixton, and at 2.17am to reports of a stabbing in nearby Acre Lane.
In Acre Lane, a 33-year-old man was found with multiple stab wounds and taken to hospital where he remains in a life-threatening condition.
Specialist crime officers were at the scene of the shooting within four minutes of the call, the Met said.
The London Ambulance Service said: "We treated four patients at the scene.
"We took two of them to a major trauma centre and the other two patients to a local hospital."
No arrests have been made but officers are working to identify those responsible, the Met said.
Several police officers could be seen searching an area of grass outside the Southwyck House estate on Coldharbour Lane.
Estate resident Robert, 40, who did not want to give his surname, said he believed the incident happened during a "packed" barbecue party.
Detective Chief Inspector Allam Bhangoo, who is leading the investigation, called the shooting an "act of indiscriminate violence".
DCI Bhangoo added: "We understand how concerning this incident will be for the local community and want to reassure residents that officers are working at pace to identify those responsible."
Read more from Sky News:
Starmer says some pro-Palestine marches could be stopped
Teen arrested after Peter Kay arena show evacuated
There will be an increased police presence in the area over the coming days.
The Met is appealing for anyone who witnessed the incident or has footage to contact them.
(c) Sky News 2026: Man in life-threatening condition among four injured in Brixton after 'indiscriminate' drive
Summer travel plans: What changes has the government announced and how will they affect you?
Two women die while trying to cross Channel in small boat
King has Midas touch with Trump, but benefits for Britain remain to be seen
Teenager charged after bomb hoax at Peter Kay show
Boy, 15, charged after street brawl leaves two teens with possible life-changing facial injuries
Local elections could see council seats won on record-low vote shares
'It felt like abandoning my wife': Why fathers think two weeks paternity leave is a 'joke'
Starmer says some pro-Palestine marches could be stopped
