A motorcycle has burst into flames after being struck and dragged in a hit-and-run crash at Mitcham, in Melbourne's east, leaving the driver with life-threatening injuries.

The police helicopter was brought in to search for the driver involved. ( ABC News: James Hancock )

Witnesses said a black four-wheel drive sped down Glenburnie Road about 4:15pm, failed to give way and hit the motorcycle which was travelling on Orient Avenue.

The motorcycle was dragged up to 60 metres and was trapped under the four-wheel drive, which had been stolen.

The driver then reversed and fled the scene and the motorbike burst into flames.

Resident Denyse Ward said it was a shocking scene.

"[It was] unbelievable, just something you never ever want to witness," she said.

"I would hate to have been right up close with it because I stayed back and [it was] unbelievable."

Police said the driver fled and the car was later found abandoned nearby on East Link at Scoresby.

Witnesses said up to five youths were seen running from the car.

The motorbike rider suffered life-threatening injuries in the incident. ( ABC News: James Hancock )

Police believe they went on to rob a home at Scoresby and steal a white Toyota Camry.

The police helicopter has been brought in to search for the individuals, while the motorcycle rider is in a critical condition at the Alfred Hospital with life-threatening burns.

Victoria Police Detective Senior Sergeant Gerard Clanchy appealed to those involved to give themselves up.

"This is a terrible tragic event for the motorcycle rider. He's just riding as he normally should and out … comes a black BMW… [it] does not give way. It's a tragic incident," he said.

"We are searching for them … and they will be caught but it's in their interest to come forward."