A 21-year-old woman who was struck by a vehicle that fled the scene may have already been laying on the road when the vehicle approached her, Toronto police said.

It happened on Danforth Road, near St. Clair Avenue and Kennedy Road, just before 3 a.m., according to the Toronto Paramedics Service.

The woman has been rushed to hospital with what police are describing as life-threatening-injuries.

"The woman is 21 years of age. She is in what I would call grave condition," Const. Clint Stibbe told CTV Toronto.

In security camera footage obtained from nearby businesses, the woman appears to be walking on the east side of Danforth Road, just south of St. Clair Avenue when she proceeds to cross into the northbound lanes. The woman suddenly disappears from view as she crosses into the southbound lanes.

The video shows a vehicle approaching from the southbound lanes about 20 seconds later. As the light from the vehicle illuminates the road, the security camera footage shows what looks to be a figure on the ground.

The vehicle did not slow down or stop after the driver drove over the figure.

Another 20 seconds later, a driver who was passing by made a U-turn when they noticed the woman on the road. The driver, who did not want to be named, told CTV News Toronto he initially thought the victim might have been an animal that had been struck and left on the road.

"I just, she did not look well," he said. "People were still trying to drive by as this woman was laying almost dead in the road.'

Police are searching for a vehicle they say was involved in the incident. The vehicle is described as an older model Toyota Sienna minivan, possibly a model that dates back to the late 90s.

“If you do believe that there’s some chance you may have been involved in this collision, we ask that you contact us as soon as possible,” Stibbe said.

Police are also trying to determine whether the victim was involved in some sort of dispute just before she began crossing the road and if that incident had factored in the collision.

Anyone with information pertaining to the incident should call Traffic Services at 416-808-1900.

With files from Tamara Cherry.