The Tokyo metropolitan region saw signs of a fifth coronavirus wave on Saturday, with daily cases in the capital and a neighboring prefecture hitting nearly six-month highs, less than a week before the opening of the Tokyo Olympics.

In Tokyo, 1,410 new COVID-19 cases were confirmed, marking the highest single-day spike since Jan. 21 and topping 1,000 for the fourth straight day.

In neighboring Kanagawa Prefecture, new cases reached 539, surpassing 500 for the first time since Jan. 24.

New infections in Tokyo, which is currently under a fourth COVID-19 state of emergency amid a resurgence of infections, rose from a week earlier for the 28th consecutive day, and the seven-day rolling average of new cases hit 1,012 per day, up 40.5 percent from the previous week, according to data from the Tokyo government.

With the Olympics opening ceremony set to take place on Friday, public concerns remain high that the games could become a superspreader event with the spread of the highly contagious Delta variant of the coronavirus, first found in India.

Health experts advising the metropolitan government said earlier in the week that the moving average could jump to 2,406 per day by Aug. 11, shortly after the Olympics end on Aug. 8.

If Tokyo's daily cases hit more than 2,000, it would be the first time since mid-January when the capital was in the midst of a third wave, so far the worst in terms of the spread of infections.