TOKYO (Kyodo) -- A woman in her 80s infected with the new coronavirus died Thursday, becoming Japan's first confirmed fatality, the health minister said, as more cases of infection were reported besides the hundreds on a quarantined cruise ship near Tokyo.

The Japanese woman from Kanagawa Prefecture, just southwest of the capital, who had not traveled overseas recently, was found to be infected with the virus after she died, health minister Katsunobu Kato said at a press conference.

The woman had been diagnosed with pneumonia and hospitalized since Feb. 1, the health ministry said, adding her breathing deteriorated on Feb. 6.

She was the mother-in-law of a Tokyo taxi driver whose infection with the virus was confirmed Thursday, according to a government official.

The driver in his 70s was quoted as saying by a Tokyo metropolitan government official that he had not transported foreign visitors in the two weeks before he first showed symptoms on Jan. 29 and health authorities are seeking to determine how he got the virus.

The government is wrestling with the spread of the pneumonia-causing virus. On Thursday, 44 additional infections were confirmed aboard the Diamond Princess cruise ship docked at Yokohama with thousands of passengers and crew remaining confined to the quarantined vessel.

In Wakayama Prefecture, a surgeon in his 50s became the first doctor in Japan to be infected with the virus, the local government said. It is not known whether he had close contact with visitors from China, the epicenter of the outbreak.

The latest cases, also including a Japanese man in his 20s from Chiba Prefecture who tested positive on Thursday, bring the total number of confirmed infections to 251 in the country. The bulk, 218, are passengers and crew of the Diamond Princess docked at Yokoyama.

The tally includes foreign tourists visiting from Wuhan, the epicenter of the viral outbreak and a Japanese bus driver who had close contact with Chinese tourists in Japan.

Medical experts say elderly people and those with chronic diseases are more likely to see their health conditions deteriorate due to the virus.

Still, the gradual rise in the number of infected people with no apparent records of traveling to China or having contact with those from virus-hit Wuhan and its neighboring areas has raised a sense of vigilance.

The health minister struck a cautious note about the situation, saying more data are necessary "from an epidemiological standpoint to say infections are growing across the country."

Prime Minister Shinzo Abe said the government will spend a total of 15.3 billion yen ($140 million) on such emergency measures as developing rapid testing kits. It will also make sure over 600 million masks are supplied a month.

Amid concern that a prolonged isolation on the cruise ship would worsen the health of people with pre-existing conditions, the government has decided to allow elderly passengers suffering from chronic illnesses to disembark earlier than scheduled if they test negative for the virus.

The roughly 200 passengers aged 80 and over on the Diamond Princess may be allowed off the ship as early as Friday, depending on their wishes and health condition, Kato told reporters, adding those with pre-existing conditions have already undergone screening.

Those allowed off the ship will stay at facilities arranged by the government until the isolation period ends next Wednesday. The more than 3,500 passengers and crew were originally scheduled to be confined aboard the ship through that day.

"There are some people whose health may deteriorate by staying (aboard) for an extended period," said Kato, while indicating the ministry may lower the age for people allowed to disembark.

After a male passenger in his 80s was found to be infected with the virus after leaving the vessel in Hong Kong, the ministry has checked the health of all those still on the ship, testing those with symptoms and others who came in close contact with them.

The ministry has since requested that people stay in their cabins to prevent the virus from spreading after taking those infected as well as those who fell ill to hospitals.

But as the days mount up without sufficient cleaning services and medical support, there have been growing calls from the remaining passengers for more doctors to come on board.

Meanwhile, the first group of Japanese nationals evacuated from Wuhan on a government-chartered aircraft amid the outbreak was allowed to go home Thursday after a little over two weeks of isolation.

A total of 197 people had been quarantined at a hotel in Chiba Prefecture, near Tokyo, and government facilities since they returned on Jan. 29 from the Chinese city at the center of the outbreak.

They all tested negative in their final virus examination conducted Tuesday after completing a 12.5-day monitoring period for the virus.

The health ministry said 199 evacuees on the second chartered aircraft that arrived on Jan. 30 are also free to return home as their test results showed they were not infected.

"I appreciated the kind treatment we were shown by government officials and people at the hotel. I was able to spend my days without much stress," said a man in his 30s from Mie Prefecture who was among the evacuees. "I want to thank the local people who have encouraged us too."

The Tokyo government said it will make available 50 temporary public housing units free of charge for those who do not immediately have a place to stay.

The outbreak has already claimed more than 1,300 lives in China, with the number of people infected with the virus on the country's mainland close to 60,000, according to its health authorities. The World Health Organization has named the disease COVID-19.