At least 19 people have been taken to hospital after a strong smell was reported at a shopping complex in Tokyo, according to media reports.

A police spokesperson said a man had sprayed a substance at a cash machine on the ground floor of the building in the luxury Ginza 6 shopping centre on Monday.

The substance is believed to have been an irritant spray, identified by authorities as likely containing capsaicin - which is found in chilli peppers.

Police are still looking for the suspect, national broadcaster NHK reported.

People near the scene reported feeling their throat become painful and itchy, with one 70-year-old woman telling AFP that it 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."

A large emergency response was present at the scene, including police officers, firefighters and ambulance workers.

The road in front of the centre was blocked off following the incident.

Officials dressed in hazmat suits were seen bringing people out of the shopping centre.

Photographs of the scene show cordons in place, with emergency workers hanging sheets of tarp around part of the mall.