Japan is planning to set a cap of 10,000 fans at sports events ahead of the Olympics, a cabinet minister said Wednesday, as organisers weigh how many domestic spectators can attend the Games.

The proposed measure would come into force after a Covid-19 state of emergency in Tokyo and other parts of the country ends on June 20, and would last until the end of August, said Yasutoshi Nishimura, the minister in charge of virus measures.

It would limit spectators to 50 percent of a venue's capacity or 10,000 people, whichever is smaller, he said. The plan is expected to become official later this week.

"It is important that we maintain thorough anti-infection measures to prevent a rebound in cases, especially as we foresee a spread of the Delta variant," Nishimura told a government advisory panel, which endorsed the plan.

The move could set the boundaries for a decision by Olympic organisers on how many domestic fans -- if any -- can attend Games events when Tokyo 2020 kicks off on July 23. Overseas spectators have already been banned.

Japan has seen a comparatively small virus outbreak, with slightly more than 14,000 deaths despite avoiding harsh lockdowns.

A decision on whether domestic fans can attend the Games is expected in late June
A decision on whether domestic fans can attend the Games is expected in late June AFP / Behrouz MEHRI

But its vaccination programme has moved slower than many other developed nations, with just over five percent of the population fully inoculated so far.

The decision on Olympic spectators is expected only after the virus emergency in Tokyo ends on June 20 and the government confirms what restrictions will replace it.

Recent reports have said "quasi-emergency" measures could be introduced, including curbs on the sale of alcohol or limited opening hours for bars and restaurants.

Experts and officials have expressed concerns that huge crowds attending the virus-postponed Games could accelerate the spread of Covid-19 after the emergency measures end.

Takaji Wakita, head of the advisory panel, warned of possible surges of infection in the near future as people start to go out more in some regions, including Tokyo.

"When the government lifts the state of emergency, it's important that restrictions are lifted gradually," he told reporters on Wednesday after the panel met.

Under the current state of emergency, spectators are capped at 5,000 people or 50 percent of a venue's capacity, whichever is smaller.

Coronavirus