By Agence France-Presse
Commuters in the bustling Japanese metropolis battled home through flurries of snow as the worst of the weather so far hit during evening rush hour.
"At least 67 people have been injured in snow-related accidents in Tokyo and the number is expected to increase further as calls for ambulances have continued," a spokesman with the city's fire department told AFP.
More than 330 domestic flights departing from and arriving to airports in the Tokyo region were cancelled due to the bad weather, while some regional trains were also suspended, local news reports said.
Japan's northern regions frequently see heavy snow but such weather is rare in Tokyo.
Large crowds struggled through the snow at Shinjuku, the world's busiest train station, as the nightly rush hour began.
Television footage showed commuters forming long queues at bus stops at another district, Shibuya, as snow blanketed the city.
The weather agency only issues a heavy snow alert when there are fears there could be damage o property or disruption to traffic.
"In Tokyo, we also warn of heavy snow if the snow is expected to accumulate more than 10 centimetres (4 inches) in 12 hours," Sakiko Nishioka from the weather agency told AFP.
The last time the alert was issued, in February 2014, Tokyo saw 27 centimetres of snow.
The country's northern regions that often see heavy snow have a higher bar for the warning.
This prompted some mockery on Japanese social media, with one user noting "public transport is paralysed with such little snow in Tokyo and a flood of people cannot go home.
"People in Asahikawa (in Hokkaido) live as if the snow didn't exist."