WA Police are still investigating the August 17 Indian Ocean Drive crash near Breton Bay, in which three people died, and another serious crash last Saturday near Clover Road, Yanchep.
According to police, a white Subaru Outback wagon was travelling south on Indian Ocean Drive about 3.20pm on August 26 and a Toyota Landcruiser Prado travelling north when the two vehicles collided head-on near the junction of Clover Road.
St John Ambulance took an 18-year-old man, who was driving the Subaru, and a 47year-old woman, who was a passenger in the Toyota, to Royal Perth Hospital where both remained in a stable condition yesterday.
They also took the 49-year-old man, who was driving the Toyota, to the hospital on Saturday and he was discharged that day.
Anyone with information on either crash can call Crime Stoppers on 1800 333 000.
The crash on Indian Ocean Drive in Yanchep.