Hidemasa Nakamura, Games delivery officer for Tokyo 2020, claims it will be "dangerous" for crowds to gather along the route and insists more stringent COVID-19 countermeasures will be in place.

The men’s and women’s marathon events are scheduled to start at 6.30am local time on Sunday (September 5) prior to the Closing Ceremony of the Paralympics.

With the route taking place in Tokyo, organisers are fearful the Japanese public - who have been banned from going into venues in areas under a state of emergency as part of anti-virus measures at the Games - will converge on the roadside to support the athletes.

Tokyo has been under a state of emergency since July 12 in a bid to curb rising coronavirus cases but infections are continuing to increase with more than 3,000 reported yesterday.

Japan is experiencing its biggest wave of the pandemic since it began last year.

More than 90 per cent of the cases in Japan are suspected to be the Delta variant, which is more transmissible than previous strains.

"The fact we have seen an increase in the Delta variant, we need to establish measures for the marathon," said Nakamura.

"We do understand that this is the final event of the Games and it is being held within Tokyo so there is a high probability that people will try to gather.

"As it is a Sunday, people may be out on the road.

"Even for those there for other reasons, given that the Delta variant is quite infectious, we would ask them not to speak in loud voices and cheer on."

The extra measures to combat the spread of the Delta variant include increasing social distancing from 1.2 metres to 1.8m and cutting conversation times without masks from 45 minutes to 20 minutes.

Nakamura said Tokyo 2020 will be staging an "intense" media campaign, with mascot Someity playing a "vital" role in spelling out the COVID-19 protocols for the marathon events.

Organisers are set to distribute fliers, put in place digital signage at around 98 sites in Tokyo and make announcements in train stations along the marathon course.

Social media is also expected to be used to tell the Japanese public to watch the event at home.

About 100 COVID-19 staff members are set to hold placards, telling people to stay away from the race and keep moving.

Additionally, from two hours before and after the last runners have passed, Tokyo 2020 said it will use 1,000 volunteers to hold up hand-held signs at nearby stations to remind people to refrain from watching the races on the roadside.

"Looking at what happened in Sapporo during the Olympics, the start line, finish line and halfway point tended to get more crowds," said Nakamura said.

"Those are the areas we are going to focus on.

"The TMG (Tokyo Metropolitan Government) staff members are going to work together with us to ensure we send out a strong message in those areas to stay away from the race."

Nakamura insisted organisers would be prepared to be "firmer in our approach" should people not adhere to the COVID-19 rules.

 "If we get crowds, that is going to show up on social media," said Nakamura.

"We are going to take efforts to gather information and our staff members are going to monitor social media to see what is happening on the day.

"If we do get large crowds, that is dangerous - not just in terms of COVID, but purely dangerous so that is something we need to work with TMG on.

"If we do end up getting a situation like that, the staff members are once again going to call out to the public asking them to disperse."

Mikako Kotani, sports director of Tokyo 2020, added: "I understand that the general public want to get close to the athletes and cheer them on but please don’t cheer.

"The top priority is safety.

"We want to end the Games on a high and ensure it is safe and secure."