The number of COVID-19 infections reported in Japan topped 1,500 on Sunday, including about 700 cases from the Diamond Princess cruise ship that was quarantined near Tokyo, as the government worked to curb the spread of the virus through various steps including asking people to avoid mass gatherings and implementing travel restrictions.

The Hokkaido Prefectural Government announced Monday that a man in his 80s who had been infected with the virus died, bringing the total number of deaths to 32. Authorities in Hokkaido also said four people newly tested positive.

The Niigata Municipal Government said a woman in her 50s who works at a day care facility had been confirmed as infected, after a man in his 80s who uses the facility tested positive on Saturday.

Authorities have identified 15 clusters of infections, 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 more in red, 10 to 49 in blue, and five to nine in green.

The only cluster with 50 or more people shown as 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 have been 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 yakatabune roofed boat, and Aichi Prefecture, where the virus was contracted at a welfare facility and a gym.

Small clusters of five to nine people have been identified 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 areas where clusters of infection have occurred in order to contain the virus.

Japan has the ninth-largest number of infections in the world, behind China, Italy, Iran, South Korea, Spain, France, Germany and the United States, according to a Kyodo News tally based on information including data released by each government.

Among the newly reported cases in Japan, two men who tested positive after arriving at Haneda Airport in Tokyo had been to Italy, while a boy in the northernmost island of Hokkaido also tested positive for the virus, according to the health ministry.

In a bid to contain the outbreak and minimize its potential impact on the economy, Prime Minister Shinzo Abe has asked all schools in the nation to shut until spring break ends in early April, and for big sports and cultural events to be canceled, postponed or scaled-down.

RELATED PHOTOS The health ministry has released on its website a map of Japan showing where clusters of infected cases have been confirmed. | KYODO