Roe Highway: Two-car crash shut down Perth highway

TWO people have been seriously injured in Perth's south-east.

According to witnesses, two vehicles collided at the Roe Highway and Tonkin Highway shortly before 12.30pm on Saturday.

Paramedics remain at the scene treating two people.

Main Roads has confirmed Roe Highway is closed westbound.

Motorists in the area are warned to expect significant delays.

Those heading on the Tonkin Highway off-ramp are impeded by the crashing crews working to clear the wreckage.