Seven people were injured but conscious after a car barreled through a busy area of downtown Nagoya, central Japan, on Tuesday, local authorities said.

The two male and five female victims, including one believed to be an infant, have been taken to hospital for further examination.

Police arrested the driver, Akemi Nakada, 74, at the scene and are investigating the cause of the incident.

A passerby called emergency services around 1 p.m., saying there was a "car running wild" in the city's Sakae district and that several people were hurt, according to the authorities.

According to a man in his 50s who was waiting at a traffic light near the scene, the car emerged from an underground parking lot and paused before abruptly accelerating, continuing off the road and onto a sidewalk on the opposite side before it was forced to a halt after it ran over a bollard.

The driver appeared distressed and was saying, "What should I do? What should I do?" the man said. "It's scary because you never know what will happen or where," he said.

The car was found partially suspended by the traffic bollard in the vicinity, its front having sustained heavy damage.

Sakae is one of Nagoya's principal commercial areas, containing many businesses and entertainment facilities.