Police have said that the 39-year-old male pedestrian who was hospitalised suffered serious injuries described as "potentially life-changing".

The 76-year-old woman - the driver - and the eight-year-old child - a pedestrian - were also taken to hospital.

South Wales Police said an investigation into the incident is under way.

Anyone who was at the location and may have witnessed what happened is asked to contact police, quoting reference number 2600162925.

The collision took place at Cardiff Gate Services, at junction 30 of the M4 in the Pontprennau area of the city, at around 11.45am today (Monday).

A witness told Wales Online the incident involved a black BMW car striking people sitting at a table at Cardiff Gate Services before hitting the main building.

"It was awful," the witness said. "About 15 people were trying to lift the car off."

She said the front window of the building was shattered in the impact.

"I imagine the driver had a medical emergency as I can’t understand how they went into the building at that speed," the witness added. "All emergency services are there."

One witness told Wales Online: "The car very nearly knocked over our 13-year-old at the top of the car park - I had to yank her out of the way - and then about six or seven seconds later, it hit the pedestrians and the service station.

"There was this almighty smash and the car actually went through the window. I can still hear the screams in my ears. My partner rushed down with some other guys and lifted the vehicle out of the window."

South Wales Police said in a statement: "We are currently dealing with an incident at the Cardiff Gate Services. It is understood a car collided with a retail premises on the site.

"Three people have been taken to hospital including an 8-year-old child and a 39-year-old man, who were both pedestrians, and a 76-year-old woman who was the driver of the vehicle. It is understood none of the injuries are life-threatening.

"An investigation into the incident is underway. Anybody who was at that location who may have witnessed what happened is asked to make contact – please give reference 2600162925."