Tokyo Governor Yuriko Koike wears a protective face mask during a press preview of a hotel that has been designated to accommodate asymptomatic people and those with light symptoms of the coronavirus disease (COVID-19) to free up hospital beds and alleviate work by nurses and staff members, in Tokyo, Japan on May 1, 2020. (Photo: Agencies)

TOKYO－Japan has approved a safer and easier saliva test for COVID-19 as the Tokyo municipal government issued an alert after confirming the highest daily tally of coronavirus infections in weeks.

Yuriko Koike, the capital's governor said the alert is a way of urging residents to remain cautious but doesn't alter the city's plan to gradually reopen the economy.

There were 12 new infections reported in the capital on Wednesday and 34 on Tuesday, a big surge since Japan fully lifted its state of emergency last week.

"We want to continue resuming social and economic activities while preventing the spread of COVID-19. We'll need cooperation from all residents," Koike said.

Meanwhile, Japan's health ministry on Tuesday approved the use of a polymerase chain reaction coronavirus test using saliva, thought to be safer and easier to administer, to be used alongside the current tests which swab mucus from the back of the nostril.

The test kits, which will be covered by national health insurance, are to be used for testing patients within nine days of exhibiting symptoms.

Separately, a team of Japanese researchers has succeeded in creating miniature bronchi－passageways that conduct air into the lungs－from human cells, paving the way for them to be used to study the virus and help develop drugs.

Elsewhere in Asia, South Korea said on Wednesday it has approved the emergency use of Gilead Sciences' remdesivir to treat COVID-19 after a government panel last week cited positive results for the anti-viral drug in other countries.

Remdesivir, administered intravenously in hospital, is a drug that shows improvement in COVID-19 patients in formal clinical trials.

Under guidelines by South Korea's Ministry for Food and Drug Safety, doctors can administer one dose of remdesivir a day, with five doses overall for patients with moderate symptoms, and 10 doses for those with severe symptoms and who need oxygen support.

South Korea had recorded 11,590 cases and 273 deaths by Tuesday.

Folk dancers sell face masks for a living in Rawalpindi, Pakistan, on Tuesday, as celebration parties have been temporarily banned to curb the spread of the coronavirus.

In Pakistan, another lawmaker, Mian Jamshed Kakakhel, died on Wednesday after testing positive for the virus.

So far, four Pakistani lawmakers have died due to the virus, which has infected 80,463 people in Pakistan and killed 1,688 since February.

In Africa, a South African court ruled on Tuesday that the lockdown regulations in the country are "unconstitutional" and "invalid".

"Some of the regulations promulgated by the government simply did not meet the rationality test in preventing the spread of COVID-19," the North Gauteng High Court said in its ruling.

The court gave the government 14 days to amend and republish the regulations. In response, the government said in a statement it will study the judgment.

Wang Xu in Tokyo,Liu Xuan in Beijing, Xinhua and agencies contributed to this story.