Tokyo on Tuesday said it will move away from numerical targets to contain Covid-19 and rely more on the advice of a committee of experts, to try to control the novel coronavirus and avoid another economic slowdown.
The metropolis, with a population of 14 million, has sought to keep new cases below 20 a day since Japan lifted a state of emergency on May 25, but has had five straight days of more than 50 new cases as of Tuesday, when 54 infections were reported.
Tokyo is two weeks into a final phase of loosening coronavirus restrictions and officials have repeatedly said they see no need to declare a new state of emergency.
They also say the medical system can handle current cases and that increased testing partly explains the rising infections.
"It's an extremely different situation from what it was at the end of March when patients were increasing rapidly, but we still must be watchful," Governor Yuriko Koike told a news conference, where she announced the new measures would start on Wednesday.
Under the new guidelines, Tokyo will move away from strict numerical targets to determine if new restrictions are needed. Instead, a group of experts will evaluate the situation on a weekly basis.
"Our medical and testing systems have both been fortified," Ms Koike said. "We are aiming to be able to both keep on top of the virus and keep economic activity going."
Tokyo, in common with the rest of Japan, has so far had a lower rate of infection than many countries.
The capital has recorded 6,100 cases and some 325 deaths, while Japan as a whole has had nearly 19,000 diagnosed with 973 deaths.
Ms Koike, whose popularity has surged as she has dealt with the coronavirus, is running for re-election on July 5. Her campaign has been mostly digital to avoid large gatherings.