Child belt up warning

Police say parents need to ensure their children do not become "projectiles" in their vehicles after an unrestrained thee-year-old girl was injured in a Yangebup crash yesterday.

The girl was lying down in the back seat of her mother's Honda Civic when they were T-boned by a Hyundai Getz at the intersection of Beeliar Drive and Dunraven Drive about 6.30am.

Police said the car did not have a child seat.

Children aged to seven years are required to be seated in a child restraint or booster seat in WA.