A man was removed from a domestic flight in Japan after refusing to wear a mask on the plane.

Carrier Hokkaido Air System says the crew spotted the man without a mask before takeoff on the flight from Okushiri Airport to Hakodate Airport in Hokkaido, northern Japan, at around noon on Saturday.

Before and after her first match in the US Open, Japanese tennis star Osaka Naomi wore a face mask bearing the name of a Black woman who was fatally shot by police in the United States in March.

The Grand Slam tournament opened in New York on Monday with various anti-coronavirus measures in place. No spectators are allowed, and players and tournament officials have been tested for the virus.

Japan's Prime Minister Abe Shinzo has worn a face mask at a meeting of the Council on Economic and Fiscal Policy as a precaution against coronavirus infection.

Other members including Cabinet ministers and private-sector representatives also wore masks at the meeting on Tuesday. Their seats were separated more than usual.

Japan's ban on the price-gouging resale of face masks came into effect at midnight on Saturday. But manufacturers expect the shortage to continue for some time.

The ban is aimed at preventing the hoarding of masks for resale at inflated prices. The activity is thought to have contributed to mask shortages.

Japan's ban on the price-gouging resale of face masks came into force on Sunday. Tokyo took the measure as masks have been in short supply amid the coronavirus outbreak.

Violators will face penalties of up to one year in prison or a fine as high as about 9,500 dollars.

A ban in Japan on the resale of face masks at marked-up prices is set to go into force from Sunday. The government has approved the measure, as the masks are in short supply amid the coronavirus outbreak.

Violators will face penalties of up to a year in prison or a fine as high as one million yen, or about 9,700 dollars.

Japanese government officials say a growing number of face masks are showing up on online auction and shopping sites. The surge comes ahead of a legal amendment that will ban reselling the items.

The officials at the industry ministry say hoarders are fetching high prices for the masks, amid a serious shortage.

Japan's top government spokesperson says the supply of face masks will increase to more than 600 million per month from March amid a severe shortage across the country.

Chief Cabinet Secretary Yoshihide Suga told reporters on Thursday that the government is working to resolve the shortage as soon as possible while closely monitoring mask production and distribution.