Japan has found 15 clusters of people infected with the pneumonia-causing novel coronavirus, according to the health ministry, which released an online map showing where they are located in the country as of noon Sunday.

Based on analysis by Hitoshi Oshitani, a virology professor at Tohoku University, and other experts, the map indicates clusters of 50 people or over in red, 10 to 49 in blue, and five to nine in green.

(Photo taken on March 4, 2020, shows an indoor music venue called Soap Opera Classics Umeda in Osaka. Some people were confirmed as infected with the new coronavirus after visiting the venue.)

The only cluster with 50 or more people infected is in Osaka Prefecture, where infections spread from events held at live music clubs, according to the map.

Clusters of 10 to 49 people are found in 10 locations, including Hokkaido, where infections spread from a live music bar, Tokyo, where the people gathered for a new year party on a boat, and Aichi Prefecture, where the virus was contracted at a welfare facility and a gym.

Small clusters of five to nine people were found in four locations, including Chiba Prefecture, where infections were found among those at a gym and a welfare facility.

The ministry has dispatched health experts to the areas where infection clusters occurred to contain the virus.

The number of infections reported in Japan has topped 1,500, including about 700 cases from the Diamond Princess cruise ship that was quarantined near Tokyo.