Commuters wear face masks to protect themselves from air pollution and the spreading coronavirus in Bangkok, Thailand, Feb 4, 2020. (GEMUNU AMARASINGHE / AP)

BANGKOK/SEOUL - Thailand confirmed six new cases of the new coronavirus on Tuesday, four of them Thai nationals and two Chinese, bringing the total to 25, the highest number outside China.

Singapore has reported 6 more cases of a newly identified coronavirus, including four domestic transmissions, taking its tally of infections to 24

The four Thais included a couple who visited Japan and two drivers who picked up Chinese passengers in Thailand, Suwannachai Wattanayingcharoenchai, director-general of the Department of Disease Control, told reporters.

It was not clear whether the couple contracted the virus in Japan or after returning, Suwannachai said.

One of the infected Thai drivers, a 70-year-old, also had tuberculosis and was transferred into government care from a private hospital on Monday with worse condition than the others.

The other driver was tracked down by Thai authorities after being identified as one of the people in contact with an infected Chinese tourist, Suwannachai said.

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Thailand confirmed its first case of human-to-human transmission on Friday when a taxi driver tested positive.

Thailand’s total 25 cases consist of six Thais and 19 Chinese. Seventeen remain in hospital and eight have gone home, according to the health official.

Earlier on Tuesday, South Korea reported a 42-year-old woman has tested positive for coronavirus after visiting Thailand, the first foreign tourist reported to have been infected after a visit to the southeast Asian nation. It was not clear yet where she had contracted the virus.

The woman, identified only as Patient 16, flew back to South Korea on Jan 19 after traveling in Thailand, the Korea Centers for Disease Control and Prevention (KCDC) said in a statement.

Treated since developing chills and other symptoms from Jan 25, the woman did not improve until Sunday, the KCDC added in a statement, and was confirmed positive on Tuesday.

In the statement, the KCDC did not explicitly rule out a visit to China by the patient, and KCDC Director Jeong Eun-kyeong declined to comment further.

Tanarak Plipat, deputy director-general of the Thai Department of Disease Control, said the woman could have contracted the virus in Thailand.

“It’s possible because the virus is already spreading domestically in Thailand,” Tanarak said.

Singapore virus tally hits 24

Singapore has reported six more cases of a newly identified coronavirus, including four domestic transmissions, taking its tally of infections to 24, the health ministry of the southeast Asian city-state said on Tuesday.

The outbreak has killed more than 420 people, spread round the world and fuelled fears for global economic growth, with neighbouring financial centre Hong Kong reporting its first coronavirus death on Tuesday, only the second outside the Chinese mainland.

“Though four of these cases constitute a local transmission cluster, there is as yet no evidence of widespread sustained community transmission in Singapore,” the health ministry said in a statement.

All four cases were linked to a health products shop that primarily serves Chinese tourists, the ministry added.

The other two infections were in Singapore residents evacuated on Thursday from the central Chinese city of Wuhan, where the virus is believed to have surfaced late last year.

“What we hope we will be able to do is contain the situation in Singapore,” said Professor Tan Chorh Chuan, the ministry’s chief health scientist.

“We have a small cluster, we should ring fence it.”

Earlier, Singapore had reported 18 cases of the virus, all with a history of recent travel to Wuhan.

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One patient had been discharged and another could follow in the next few days, said ministry official Kenneth Mak.

“Five patients have oxygen to support breathing but ... none are critically ill,” added Mak, the ministry’s director of medical services.

The situation called for close monitoring, Tan said.

“What will be really important is how the very extensive measures that have been taken in China to contain the infection ... pan out over the next few weeks,” he said.

“But we need to monitor the situation very closely, it’s very dynamic.”