At least nine people were killed and four injured when a car ploughed into pedestrians in the center of the South Korean capital, Seoul.

Police said the accident occurred at about 9:27 p.m. local time at an intersection near Seoul City Hall, a typical busy street in the city.

According to the Yonhap news agency, the vehicle that hit the pedestrians waiting at the traffic control was driven by a man about 68 years old.

Police said the man, whose name was not released, had been arrested and would be investigated on charges of manslaughter.

The driver told investigators his car accelerated suddenly and unintentionally.

Police said his car would be sent to the national forensics agency for examination.

Of the nine fatalities, six people died at the scene while three were taken to hospital due to cardiac arrest, where they were pronounced dead.

Photos from the scene showed a black sedan that was badly damaged and was towed away. Guardrails on the side of the road were flattened to the ground.

Seoul police said a man was driving the wrong way and collided with two other vehicles before fatally hitting a pedestrian.

The initial investigation revealed that the cause of the accident was unintentional acceleration, and preliminary examination did not indicate that the driver was under the influence of alcohol or any other drug.

South Korean President Yoon Suk Yeol ordered the Ministry of Internal Affairs to make “comprehensive” efforts to treat disaster victims.

Seoul Mayor Oh Se-hoon called it a “tragic incident” and ordered an investigation.

Upon arriving at the scene, Mr Oh issued directives to minimise further casualties and made arrangements for the bereaved families.

He ordered “the victims to be quickly transported to hospital to determine the exact cause of the accident.”

The man was reportedly a bus driver from Ansan, a city south of Seoul, and had about 40 years of driving experience.

According to the Organisation for Economic Co-operation and Development (OECD), 35% of all road fatalities were pedestrians in 2022. The number of road fatalities among pedestrians was the highest among OECD countries, but the report found that this trend has been decreasing in recent years.

The incident comes in another tragedy in South Korea, just a week after 23 people died and dozens were injured in a fire at a lithium battery factory in the city of Hwaseong, a large industrial area about 90 minutes southwest of the capital, Seoul.