TOKYO - Four people were injured after an explosion took place on Monday afternoon near Shimbashi in downtown Tokyo of Japan.

The explosion was reported at around 3:15 pm local time as a fire broke out in an eight-story building some 300 meters away from the centrally located JR Shimbashi Station, according to the local police department.

According to Tokyo Metropolitan Police Department, four people suffered minor injuries, who were two passersby and two employees of the restaurant where the explosion reportedly took place.

At the time of the accident, Xinhua reporters heard the blast while driving past an intersection less than 50 meters away from the scene, and then saw a lot of fragments flying out of a room on the second floor of the building.

A burst of smoke was spotted in the room accompanied by a slight smell of gas before the fast spread of the fire, the reporters said.

The reporters saw three injured people escaping via the emergency exit on site, with their hair and clothes partly burned.

According to the fire department, the second and third floors of the building were burned down, with some 31 engines dispatched to extinguish the fire.

The area, home to many offices and restaurants, was 300 meters to the west of JR Shimbashi Station, one of Tokyo's major interchange railway stations and only 10 minutes' walk from the Ginza shopping district.

The cause of the accident is still under investigation.