Tokyo Gov. Yuriko Koike on Tuesday unveiled a new coronavirus warning system that is based more on the advice of medical professionals instead of relying heavily on specific numerical targets, as the capital grapples with a recent uptick in the number of new cases after business and social restrictions were eased about a month ago.

For the new monitoring system designed to shed light both on Tokyo's infection situation and its medical preparedness, the metropolitan government, which confirmed over 50 new cases for the fifth day in a row, released seven criteria such as the number of people examined and the positivity rate.

Unlike the earlier "Tokyo alert" system, it has no numerical targets to trigger a public warning and the situation will be evaluated more comprehensively by the metropolitan government's "monitoring council" based on the benchmarks, which also include the numbers of new patients, hospitalized people and those in serious condition.

"It's not about turning on a switch once we hit a particular numerical target, but rather about getting a holistic picture," Koike said at a press conference.

The new system will be introduced Wednesday, first on a trial basis through early July. The council is expected to meet once a week in principle.

Under the old system, when certain conditions -- such as the daily average number of new cases exceeding 20 in a week and the ratio for unknown infection routes climbing to more than 50 percent -- were fulfilled, Tokyo had to issue an alert and light up its government building, as well as the capital's landmark Rainbow Bridge, in red.

Photo taken June 30, 2020, shows a Chinese restaurant in Tokyo's Kita Ward where mannequins are placed on seats to help customers maintain social distancing to reduce the risk of coronavirus infections. (Kyodo)

While the criteria used for the alert remain in the system, more aspects will be studied before the Tokyo government determines whether to issue a call for caution or request businesses to be temporarily closed, as part of measures to prevent the spread of the COVID-19 disease.

The latest report of 54 new confirmed cases brought the capital's cumulative total to 6,225, according to officials.

Businesses in the capital resumed operating on June 19. But Tokyo reported 60 cases on Sunday, the highest daily number since Japan lifted the state of emergency for Tokyo on May 25.

Many new infections have recently been confirmed among young people who have visited or work at nightlife establishments. Clusters of infections at the same workplaces and dining venues have also been increasing, according to authorities.

Japan saw almost 140 new cases of COVID-19 on Tuesday, bringing the total to more than 18,700, not including the 712 from the Diamond Princess cruise ship that was quarantined in Yokohama near Tokyo in February.

Tokyo's landmark Rainbow Bridge is lit up in red on June 4, 2020, to warn residents about a resurgence in coronavirus infections in the capital. (Kyodo) 

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