A four-year-old boy was slightly injured when the car being driven by his mother was involved in a pile-up in Sir Paul Boffa Street in Paola at 10.15am.
The condition of the 30-year-old woman is still being assessed,
The police said that the crash involved four cars and a route bus. No other injuries were reported.
Malta Public Transport said CCTV footage showed that a car had stopped in front of the bus. The bus stopped a safe distance behind, but the car rolled back and crashed into the bus.