Three teenage boys are in hospital, including one in a critical condition, after they were shot in north London.
Police found them with gunshot wounds near a car park in Haringey, shortly after midnight.
A 19-year-old is in a critical condition, while a 15-year-old has possibly life-changing injuries, police said.
Another boy, also 15, has injuries that are not thought to be life-changing or threatening.
Officers believe the gunman arrived in a car, carried out the shootings, then drove off.
No arrests have been made yet.
Police are appealing for anyone with information to come forward and have called for witnesses who may have seen a car driven "erratically" from the scene.
"Young men have been shot, one is critically injured and another has injuries that may mean his life has changed forever," said Detective Inspector Gemma Alger.
"We want to stop these acts of violence and we can only do this by people telling us what they know."
She added: "Even if you don't think you saw anything suspicious, if you were around and have any dashcam footage we want to hear from you."
Crime scenes have been put in place and specialist police officers are investigating.
Commander Paul Brogden said investigators would "leave no stone unturned" to find the suspect.
"This was another appalling crime, where three young black males have become victims in our capital city, two of whom are actually children," he said.
:: Any witnesses or anyone with any information is asked to call police on 101 or contact via Twitter @MetCC, quoting CAD 297/23JUL.
To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.