Japanese Prime Minister Yoshihide Suga formally declared a state of emergency in Tokyo as a precautionary measure.
It comes as Covid-19 cases in the country hit a two-month high, only two weeks away from the beginning of the Olympic Games.
The restrictions, aimed at curbing this rise in coronavirus cases, are set to be in place until August 22nd
It was reported earlier in the week that Japan's government was set to ban fans from all events at the Games, which are due to run from July 23rd to August 8th.
Organisers have already banned overseas spectators and set a cap on domestic spectators at 50% of capacity, up to 10,000 people.
They are due to convene again today to decide if any spectators will be allowed to attend, or if the games will take place behind closed doors.
Prime Minister Suga said: "Taking into consideration the effect of coronavirus variants and not to let the infections spread again to the rest of the nation, we need to strengthen our countermeasures."
In Japan, widespread opposition to the games taking place at all has been reported.
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