Tokyo confirmed 4,051 daily coronavirus cases Friday, topping the 4,000 mark for the first time since Aug. 27, the metropolitan government said.
Japan has been facing a resurgence of the virus amid the spread of the highly transmissible Omicron variant.
The seven-day rolling average of new COVID-19 cases stood at 1,950.4 per day in the capital, nearly six times higher than a week before.
The metropolitan government has projected that the average could rise to around 10,000 next week.
On Thursday, Tokyo raised its COVID-19 alert to the second highest of four levels.