A woman has been critically injured in an alleged hit-and-run by a car that ran a red light.

The 29-year-old woman was hit by a blue Hyundai at the intersection of Woodville Rd and Kirrang Ave at Villawood in Sydney’s southwest about 7.25am on Monday.

Police say she was on a pedestrian crossing with a green signal when she was hit.

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She was struck by the front right corner of the car and flung about 30 to 40 metres before coming to rest motionless on the road, police said.

The driver, who allegedly ran a red light, did not stop and kept driving south along Woodville Rd, police said.

Nearby members of the public rushed to help, shielding her from traffic and preventing other vehicles from running her over.

Acting Superintendent Tom Barnes praised the group for these actions.

The woman was treated at the scene by paramedics before being taken to Liverpool Hospital in a critical condition.

As of Monday afternoon, she was undergoing emergency surgery for head injuries and multiple serious fractures, Barnes said.

Police have released footage of the vehicle, urging the driver to come forward.

The car is described as a blue Hyundai iX35 SUV, manufactured between 2010 and 2015, with a black and yellow NSW number plate.

“It has damage to the front offside from where it struck the pedestrian, the remnants of which are on the roadway still,” Barnes said.

He added the sun was facing away from the vehicle at the time of the incident and not directly towards it.

“We’re really encouraging the driver of that motor vehicle, who no doubt is in a state of distress themselves, to come forward,” Barnes said.

“Contact the police at the soonest possible opportunity.”

Police also urged anyone with information about the vehicle involved — including repair work, suspiciously hidden damage, or any dashcam/mobile phone footage— to come forward and contact them.

Woodville Rd south bound was closed between Christiana St and the Hume Hwy following the incident, resulting in heavy traffic.

There was also a partial closure of one north bound lane.