A man is fighting for his life in hospital after a motorbike crash in Bromley yesterday (Friday, December 17).

The crash, which occurred on Mason's Hill in Bromley around 7.25pm on Friday, was one of a number of serious crashes on London's roads over the last 24 hours that left four others dead and prompted a number of police investigations.

In the Bromley incident, police and paramedics attended the scene on Mason's Hill around 7.25pm after reports of a "collision between a car and a motorcycle".

Police said the 28 year-old motorcycle rider was taken to hospital where his condition was assessed as life-threatening.

The driver of the car stayed at the scene.

Police said no arrests have been made as they continue to appeal for information: Any witness or anyone with information is asked to call the Met on 101, citing 'ref 6405/17Dec'.

Elsewhere in London on Friday and early on Saturday, four fatal collisions took place.

Crashes in Cricklewood, Northolt, Southall and Chadwell Heath led to the deaths of two pedestrians and two motorcyclists, the authorities said.

Among the victims was a 16-year-old boy who died after he was struck by a bus in Northolt, while the driver and passenger of a car involved in the fatal crash in Chadwell fled the scene and are now being sought by police.

Chief Inspector Lora John of the Met’s Roads and Transport Policing Command said the overall picture for London was "disturbing and tragic" in a statement released on Saturday.

"Each of these incidents is being investigated separately by dedicated officers," she said. "The circumstances in each case are different and none of the collisions are believed to be directly linked.

"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.

"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."

Click here for more information on the crashes from the Met Police.