Two people have been flown to a Perth hospital after a head on collision in Ravenswood, about 15 kilometres east of Mandurah.
Seven people sustained non-life-threatening injuries when a hatchback and 4WD collided at the intersection of Pinjarra Road and Murray Bend Drive at about 6.20pm.
Police will allege there were six people in the hatchback.
The Department of Fire of Emergency Services, police and St John Ambulance were at the scene for more than an hour after the incident.
Two of the people involved in the serious crash were taken to Peel Health Campus.
The extent of the victim’s injuries are unclear.
Police will continue to investigate the causes of the crash.