Japanese experts are warning the current wave of coronavirus infections is putting increasing strain on the medical system in the capital.
They say hospitals are being forced to turn away some COVID-19 patients and hotels where those with mild or no symptoms are asked to quarantine are full.
The daily tally of new cases in Tokyo has been well over the 1,000-level for much of the past week. 135 people in the capital are now in serious condition.
Public health experts report the average number of daily cases is up 65 percent this week, compared to a week earlier.
Director Ohmagari Norio of Disease Control and Prevention Center said, "The current situation may reflect an explosive spread of infections."
With hospital beds filling up, more than 8,000 people who tested positive are quarantining at home. Three have died, including two people who had pre-existing conditions.
Hospital beds for COVID-19 patients are also running low in other parts of the greater Tokyo region.
One reason is that some patients need to stay at the hospital long after testing negative, as they recover.
Even after testing negative, other hospitals are reluctant to accept these patients.
Prime Minister Suga Yoshihide is urging medical associations to help secure more hospital beds for coronavirus patients... and to prepare for a vaccination drive.
Suga said, "We need your continued cooperation to provide necessary medical assistance to those who need it."
In an effort to curb the contagion, the central government added seven prefectures to its state of emergency on Thursday. The measure will remain in place until February 7.
People are asked to refrain from non-essential outings and help reduce the number of commuters by 70 percent by working from home.
But it appeared to be business as usual in the newly added prefectures on Thursday morning, compared to the state of emergency last spring.
Some businesses are finding it hard to shift to remote work.
A bank in Tokyo developed a new system to allow employees to access confidential data from home.
It has also introduced flexible working hours. But the ratio of telework is still around 30 percent.
Misawa Toshiyuki of Asahi Shinkin Bank said, "A 70 percent reduction is a high hurdle because a certain number of staff must be in the office, including those who are at the service counter. We plan to reduce the number of in-office staff at our headquarters since they don't handle customer service."
Experts say that senior managers or leaders of industry groups should set concrete guidelines, instead of relying on the personal judgment of workers.
Health authorities reported more than 6,600 new cases across Japan on Thursday.
Over 310,000 people have tested positive in the country since the pandemic began.