A 73-year-old woman was killed and four others including a child were injured Saturday when a taxi accelerated suddenly and mounted a sidewalk in central Tokyo. The taxi driver also died in the accident.

The woman, Kumiko Kobayashi, was struck and killed while walking on the sidewalk in the capital's Chiyoda Ward at around 4:20 p.m. Hitoshi Yamamoto, the 64-year-old driver who was in critical condition after the accident, later died at a hospital, the police said Sunday.

Police believe the accident might have been caused by a sudden health problem experienced by the driver, as an emergency signal in Yamamoto's vehicle was activated.

The taxi struck two people riding bicycles — a man in his 40s and his 9-year-old daughter — before driving onto the sidewalk and hitting Kobayashi and another woman in her 60s. A passenger in the taxi in his 30s also sustained serious injuries, the police said.

Police said the taxi had stopped at a red light and did not move when the traffic signal turned green. It suddenly lurched forward after the driver of a vehicle behind blew the car horn.

The taxi came to a stop after crashing into a tree on the sidewalk without any sign the brakes had been applied, police added.

A witness was quoted by the police as saying Yamamoto seemed to have slumped forward in his seat while waiting at the traffic light.

An emergency sign had been activated on a taxi that caused a deadly accident in Tokyo on Saturday. | Kyodo
An emergency sign had been activated on a taxi that caused a deadly accident in Tokyo on Saturday. | Kyodo