Four people have died and a fifth person has been critically injured in five separate incidents on London’s roads within the space of 24 hours.

A 16-year-old boy was killed in a collision with a bus in Cricklewood, north London, at about 7.45pm on Friday while a 41-year-old man was pronounced dead at the scene after a suspected hit-and-run in Southall, west London, at about 1.55am on Saturday, police said.

A 20-year-old motorcyclist died after a crash with a car in Chadwell Heath, east London, at just after 9.20pm on Friday. The driver and passenger in the car, a grey Audi TT, made off on foot.

In another incident, a 23-year-old motorcyclist died after what is thought to be a single-vehicle crash in Cricklewood, north London, at just before 4.40am on Friday.

Another motorcyclist, aged 28, suffered life-threatening injuries in a collision with a car in Bromley, south-east London, at 7.25pm on Friday.

Chief Inspector Lora John, of the Metropolitan Police’s roads and transport policing ommand, said none of the incidents are believed to be directly linked.

She added: “However, the overall picture is disturbing and tragic. My thoughts are with the families of those who have lost their lives. They will be supported by specialist police officers in the difficult days and months ahead.

“In two of the incidents, drivers did not remain at the scene. Urgent enquiries are under way to trace them.

“The Met is committed to working with partners and the public to ensure that London’s roads are safe for everyone.

“Days like these are challenging and upsetting, demonstrating clearly how much needs to be done by all of us to stop this needless loss of life.”