A 17-year-old motorist has suffered serious burns after being struck across the legs by a thick metal wire, which had been strung across a road in Perth's southern suburbs.

Key points: Heath Prince stopped his car, got out and tried to remove the cable when another car hit it and it detached and hit him

Heath Prince stopped his car, got out and tried to remove the cable when another car hit it and it detached and hit him He says he has been told he is lucky not to have lost his legs in the incident

He says he has been told he is lucky not to have lost his legs in the incident Police are looking to speak to the occupants of a vehicle that stopped at the scene

Heath Prince was driving north on Pinetree Gully Road in Willetton shortly after midnight on December 29, when he saw a steel cable across the road near Panamuna Drive.

Police said the trainee roof carpenter applied his brakes but made slight contact with the wire, which was attached between a power pole and a no standing sign.

He got out of his vehicle and as he was trying to remove the wire another vehicle hit it, causing it to detach from the power pole and strike him across both of his legs.

He suffered serious burns to both the front and back of his legs.

It is believed the cable was stolen from the local cricket club. ( Supplied: WA Police )

"I was in agonising pain, I've come off on motorbikes and this was nothing like that. I felt like I'd just lost my legs," Heath said.

"Agonising, uncontrollable screaming, it was shocking.

"I've just dropped to the ground, I couldn't stand.

"I called my dad because I couldn't walk … I couldn't even drive … I had to get carried to the car.

"I've been told I'm lucky I didn't lose my legs … I'm just glad I'm still here today."

Heath Prince's shorts were torn by the metal wire. ( ABC News: Courtney Bembridge )

Heath said he was still recovering from the incident.

"I'm still in a bit of shock from it. It's to the point where I'm actually a bit scared to drive my car now," he said.

"Sitting down has just been agonising pain.

"I'm not going to be running around any time soon but … I still consider myself very lucky that I'm still here today, still walking around."

Stunt was much more than a silly prank: police

Detective Senior Constable Hayley Worland said the outcome could easily have been much worse.

"The first thing I thought when I saw the extent of the injuries was how lucky the victim was and how much worse it could have been," she said.

"An act like this is not simply a silly prank. Serious injury could have been caused to this victim and if not worse to someone like a motorcyclist."

The snapped cable caused injuries to the teenager's leg as he was trying to remove it. ( Supplied: WA Police )

Two people wearing grey hooded jumpers were seen running across Burrendah Park about the time of the incident.

The second vehicle stopped and remained at the scene for some time, and police are asking for the driver and occupants to come forward.

They are described as being dark skinned, while the vehicle is possibly a grey-coloured Volkswagen sedan or similar.

Police believe the cable was stolen from the Willetton District Cricket Club on December 28.