Three men are fighting for their lives after they were hit by a car that mounted the curb outside an Indian restaurant following a collision in Sydney’s west.

Emergency services were called to the intersection of Bungarribee Road and Lock Street in Blacktown about 9am.

Police said a white Toyota Corolla and a maroon Honda CR-V crashed, causing one of he cars to hit three men standing outside Desizzz Kitchen.

Three men are fighting for their lives after they were hit by a car that crashed and mounted the curb outside an Indian restaurant in Sydney's west.Three men are fighting for their lives after they were hit by a car that crashed and mounted the curb outside an Indian restaurant in Sydney’s west. (FRNSW)Three pedestrians have been rushed to hospital in serious condition after a car crash in Sydney's west.A car is on its side and a tree is knocked over. (Nine)

The men are believed to be all aged in their 30s.

Aerial vision from the crash scene shows the white Corolla on its side and a tree knocked over, and the maroon Honda stopped in the middle of the intersection.

Doctors from a nearby medical centre, paramedics, police and firefighters are all at the scene responding to the incident, according to Fire and Rescue NSW.

Paramedics treated the trio for multiple injuries before rushing them all to Westmead Hospital in critical condition.

Police have taken the drivers of both cars, believed to be aged in their 20s and 30s, to Blacktown Hospital for mandatory testing.

Officers have established a crime scene which will be examined by specialist police from the Crash Investigation Unit.

Three pedestrians have been rushed to hospital in serious condition after a car crash in Sydney's west.It is unclear at this stage how many were involved in the crash.  (Nine)

Firefighters have cleared the branches and debris on the crash site and have rendered the site safe.

Transport for NSW has confirmed Bungarribee Road has been closed in both directions between Flushcombe Road and Blacktown Road.

Diversions for buses and cars are in place, with motorists advised to expect delays.