A teenager died when a lump of concrete was thrown at the car he was travelling, causing it to crash.
Police are now carrying out a murder investigation into who was responsible for the death of Naseem Galleze.
The 17-year-old student suffered multiple injuries after the mint green Vauxhall Corsa collided with a lamppost on Saturday sometime after 3pm.
It is believed the vehicle came under attack on the Turnham Estate in Brockley, south east London, and that the block was hurled at it as he drove off.
Those suspected of throwing the concrete then escaped on foot.
Passers-by tried to help Naseem and the two friends who had been in the car with him.
Police, London Ambulance Service and London’s Air Ambulance attended and Naseem was taken to a south London hospital, where he later died.
A post-mortem examination found that his death was caused by multiple injuries, consistent with being in a road traffic collision.
The others who were travelling in the car suffered minor injuries.
The Metropolitan Police launched an appeal for information and asked anyone who saw what happened to come forward.
Four men, aged 20, 21, 23 and 19, were arrested on Sunday in connection with the investigation, and have since been bailed pending further inquiries.
Two further males were arrested on Tuesday and remain in police custody.