Around 20 people were injured at a luxury shopping complex in central Tokyo on Monday when a man sprayed a substance inside, police and fire department officials said.

Tokyo police spokesman Yusuke Koide told French news agency AFP that a man sprayed a substance at an ATM on the ground floor of the building, while a local fire department official said "around 20 people were injured" after a report of a "smell."

The road in front of the mall – located in the touristy and upmarket shopping district of Ginza – was blocked off following the incident, and fire trucks lined the street.

But shoppers continued to come and go from the building using side entrances.

An AFP reporter at the scene saw two people on stretchers being put into an ambulance, while firefighters and officials dressed in hazmat suits brought people from the mall into specialized trucks to examine them.

Public broadcaster NHK said the injuries appeared to be light.

One 70-year-old woman who was at the mall told the broadcaster that her throat started "stinging and hurting" as she approached the ATM.

"By the time I arrived, the commotion had already started, and I thought there might have been a small fire or something," she said.

"Once I went into the ATM corner, my throat felt scratchy, almost numb," she added.

Police are investigating the cause, a fire department officer at the scene said.

Violent crime is relatively rare in Japan, which has a low murder rate and some of the world's toughest gun laws.

However, there are occasional stabbing attacks and even shootings, including the assassination of former prime minister Shinzo Abe in 2022. In January, his killer was sentenced to life in prison.

In December last year, 14 people were wounded in a stabbing attack in a factory in central Japan in which an unspecified liquid was also sprayed.

Japan remains shaken by the memory of a major subway attack in the 1990s when members of the Aum Shinrikyo cult released toxic gas on trains, killing 14 people and making more than 5,800 ill.

On March 20, 1995, five members of the group dropped bags of Nazi-developed sarin nerve agent inside morning commuter trains, piercing the pouches with sharpened umbrella tips before fleeing.