Police have released shocking footage showing the moment a car ploughed into a dog walker, seriously injuring her and killing her pet.

The footage shows a woman walk her pet Millie on a lead along Doe Bank Lane, in Great Barr, Birmingham, when a Renault Clio swerves across the road and hits them, carrying them over a grass verge and out of the frame.

Two men and a woman then run back onto the road from the verge, abandoning their car before running towards a Vauxhall Astra which had stopped up ahead.

The pedestrian, who has not been named, survived but suffered serious injuries and a broken leg while her beloved dog died at the side of the road.

The video, filmed on July 22, shows the woman walking along the country road with her dog as a Vauxhall Astra drives past.

Seconds later, a blue Renault appears to swerve out of control and hits the woman on the opposite side of the road, before disappearing into undergrowth.

The black Astra, which had passed the dog walker moments earlier, stops further up the road.

Two men get out of the passenger side looking back towards the scene, while a third person, still at the wheel, puts the car in reverse.

As the Vauxhall heads backwards, two men and a woman emerge from the bushes where the Renault crashed and run onto the road.

West Midlands Police have now launched an investigation and are urging anyone with information to get in touch.

A force spokesperson said: 'We've released this shocking footage as part of an urgent appeal for information.

'The crystal-clear CCTV footage shows a number of people running away from the scene.

'We're appealing to trace them, and need anyone with information to get in touch.

'We're also trying to find the black Astra that stops further down the road.

'We believe the two cars were travelling together and the people are probably friends with each other.'

Following the incident, the 30mph road was sealed off as medics - including the Midlands Air Ambulance - treated the dog walker before taking her to Birmingham's QE Hospital.

A spokesman for West Midlands Ambulance Service added: 'A collision involving a car and pedestrian left a woman with serious injuries in Birmingham.

'The incident happened at around 5pm in Doe Bank Lane, Great Barr.

'An ambulance, a paramedic officer and the Midlands Air Ambulance from Cosford with a MERIT trauma doctor on board attended the scene.

'An off-duty nurse was on scene administering first aid to the pedestrian, a woman, who had been involved in a collision with a car.

'The woman suffered serious injuries and, once treated and stabilised on scene by ambulance staff, she was taken by land ambulance on blue lights to Queen Elizabeth Hospital Birmingham for further trauma treatment.'

Anyone with information is urged to get in touch with police via Live Chat at www.west-midlands.police.uk between 8am and midnight or call 101 anytime.

Alternatively, contact Crimestoppers anonymously on 0800 555 111 quoting log 3677 of July 22.