An infant was airlifted to hospital, while the driver, passenger, and a pedestrian were also taken to hospital.
The car, a white BMW, was seen being removed from the scene.
The police presence will be outside the hospital for a number of hours.
Withybush Hospital's director asked people not to contact the hospital for more information, and services are running as normal.
LONDON DAILY ARCHIVE
Car Hits Pedestrians Outside Withybush Hospital in Haverfordwest, Pembrokeshire
A car hit pedestrians outside Withybush Hospital in Haverfordwest, Pembrokeshire, on Wednesday afternoon.
21 June 2023 · 19:33 UTC
