The sudden rise in the number of virus cases in Tokyo and the government's strong actions immediately after the Olympic postponement have raised questions in parliament and among citizens about whether Japan understated the extent of the outbreak and delayed enforcement of social distancing measures while clinging to hopes that the games would start on July 24 as scheduled.

With the Olympics now off, many are voicing suspicion that the numbers are rising because Japan suddenly has no reason to hide them.

"In order to make an impression that the city was taking control of the coronavirus, Tokyo avoided making strict requests and made the number of patients look smaller," former Japanese Prime Minister Yukio Hatoyama said in a tweet. "The coronavirus has spread while they waited. (For Tokyo Gov. Yuriko Koike) it was Olympics first, not Tokyo's residents."

Experts have found a rise of untraceable cases mushrooming in Tokyo, Osaka and other urban areas — signs of an explosive increase in infections.

Prime Minister Shinzo Abe said Saturday that Japan is now on the brink of a huge jump in cases as it becomes increasingly difficult to trace and keep clusters under control.

"Once infections overshoot, our strategy ... will instantly fall apart," Abe warned. "Under the current situation, we are just barely holding up." He said a state of emergency is not needed just yet, but that Japan could at any time face a situation as bad as in the United States or Europe.

There was less of a sense of urgency displayed recently when many people visited parks for cherry blossom viewing, and Abe was only hinting at an Olympic postponement. But in a phone call with International Olympic Committee President Thomas Bach last Tuesday, Abe agreed to postpone the games until around the summer of 2021 because of the coronavirus pandemic.

A day later, Koike asked Tokyo residents to stay home weekends until mid-April, saying confirmed cases of the coronavirus had shot up to 41 in a day from 16 earlier in the week. On Saturday, Tokyo reported 63 new cases, another single-day record. Koike said that infections in Tokyo were on the brink of an explosive increase, and that stronger measures, including a lockdown, could be needed if the spread of the virus doesn't slow.

"Is this just a coincidence?" Maiko Tajima, an opposition lawmaker from the Constitutional Democratic Party of Japan, said during a parliamentary session last Wednesday, citing Tokyo's sudden spike.

Health Minister Katsunobu Kato said there is "absolutely no relationship" between the Olympic postponement and the number of confirmed cases. Abe cited experts as saying a big reason for the recent rise is the growing number of cases that can't be linked and a jump in infections from abroad. The prime minister told people to "be prepared for a long battle."

A day after Koike's warning, Abe convened a new task force under a recently enacted special law that would allow him to declare a state of emergency in specific areas, including Tokyo.

Japan's strategy has been to focus on clusters and trace infection routes rather than testing everyone. A guideline issued Saturday still says that tests will be conducted per clinical doctors' advice. Experts set a high bar for testing eligibility, allowing them only for those linked to clusters or those with symptoms, because they fear massive testing will fill up beds that are needed for patients in severe need, and cause a collapse of medical systems.

From Feb. 18 to March 27, Japan tested about 50,000 people, a daily average of 1,270 — fewer than the national daily capacity of several thousand. There was only a slight increase in the number of tests in the past week. In Tokyo, fewer than 2% of those who sought advice on a government hotline had been tested, according to health ministry figures. South Korea, by contrast, had tested about 250,000 people by mid-March.

Abe denied allegations that Japan had manipulated the numbers by limiting tests, or combined COVID-19 deaths with other pneumonia fatalities. "I'm aware that some people suspect Japan is hiding the numbers, but I believe that's not true," he said. "If there is a cover-up, it will show up in the number of deaths." He said doctors told him that pneumonia patients with COVID-19 can be detected by CAT-scan or X-rays.

Many Japanese experts say testing is not for everyone and should be conducted selectively in an attempt to save hospital beds for those who really need them. "Tests are primarily for people who are suspected of having the virus, and should be based on clinical judgment by doctors," said Shigeru Omi, a former World Health Organization public health expert who is on the government-commissioned panel.

Aki-Hiro Sato, a professor of information sciences at Yokohama City University, said in a recent report that Japan is now likely facing a second or third wave of the virus coming from Europe and the United States. Tokyo has about 430 cases, but Sato estimated an additional 1,000 might have been infected in Tokyo by late March if infections are accelerating at a pace similar to what's happening in other countries. Including asymptomatic or light infections, about 10,000 people might be infected, he said.

As of Sunday, Japan had 2,578 confirmed cases, including 712 from a cruise ship, with 64 deaths, according to the health ministry. About 1,000 have recovered.

Under the current law, COVID-19 is designated as an infectious disease and whoever tests positive is routinely hospitalized, but a new government guideline would allow a triage of patients, which would include self-quarantine at home.

Right now, Japan has 2,600 hospital beds designated for infectious disease treatment, including 118 in Tokyo, but about one-third of them are already occupied by COVID-19 patients, according to Satoshi Kutsuna of the Disease Control and Prevention Center. Citing the recent spike, Kutsuna said that an "overshooting of infections is just about to begin, unfortunately."

Abe has said the government would secure 12,000 beds and 3,000 ventilators to prepare for a worst case scenario.

"We fear a situation where severe patients start dying when the medical system collapses, and we must prevent that situation," Kato, the health minister, said Sunday on a talk show on public broadcaster NHK.