Japan suffered a spike in coronavirus cases after people gathered in parks on a bank holiday weekend in March when there was no lockdown in place, it is feared.

Prime minister Shinzo Abe today highlighted the Vernal Equinox weekend on March 20-22 as a possible cause of Japan's recent spike in cases.

Figures from that weekend show that Tokyo parks were busier than usual, while many people left the capital to spend the holiday elsewhere.

Japan did not impose a state of emergency until April 7, which was last night expanded to cover the whole country.

Since the long weekend, Japan has started recording hundreds of new coronavirus cases per day, having not seen more than 100 in a day beforehand. The current tally is 8,582 cases and 136 deaths.

Abe has faced criticism for imposing the measures too late, while a plan to send two face masks to every household has already been met with mockery because of the small size of the masks.

There has also been anger over a planned government handout of 300,000 yen (£2,250) to some households, which has since been changed to 100,000 yen (£750) for every household. Abe apologised for the confusion today.

This graph shows the daily number of cases in Japan. The figures have increased since late March, in a spike which the PM has linked to the long weekend on March 20-22

Japanese prime minister Shinzo Abe, pictured in Tokyo yesterday, has extended the country's state of emergency to the whole country

A graph showing the number of coronavirus deaths per day in countries when compared to their population size. The line represents a seven-day rolling average, meaning it shows trends in the data rather than precise figures. It reveals Belgium has the highest rate in the world, but ministers say this is because they are being more transparent with their data

Abe today warned Japanese people not to travel during the upcoming Golden Week holiday season, which sees four public holidays in the space of a week. The state of emergency has been extended through that week, lasting until May 6.

The emergency orders had originally been put in place for seven regions with the highest number of infections, but were yesterday expanded to all of Japan.

'It's very late. The government should have issued the state of emergency nationwide when it declared it for the seven prefectures,' said Shoichi Inoue, 58, a warehouse worker.

Regional governors can now order people to stay indoors, but there is no punishment for breaking the rules.

At a press conference today, Abe said social distancing measures had not yet achieved the necessary reduction in person-to-person contact in Tokyo.

Social contact needs to be reduced by 70 to 80 per cent, but parts of Tokyo had not yet reached that figure, he said.

According to a daily count on the website of Japan's health ministry, the country was recording around 40 cases a day in the lead-up to the Vernal Equinox on March 20.

That weekend, the number of people visiting Tokyo's Ueno Park was around 60 per cent higher than on the weekend of March 7-8, according to figures reported by the newspaper Asahi Shimbun.

There were around 2.5 as many visitors at the Shinjuku Gyoen National Garden compared to two weeks earlier, the report said, citing GPS data.

Tourist spots outside central Tokyo were also more widely visited that weekend, it is believed.

A graph showing the number of new infections in various countries, starting on the day they first recorded five infections. The graph shows a rolling average, meaning it shows trends in the data rather than exact figures. While some countries such as India, Japan and Indonesia are still rising up the chart, many countries have leveled off or are seeing infection rates fall

March 20: People sit outside in a park in Tokyo on the Vernal Equinox holiday on March 20, which is feared to have prompted the spread of the disease

April 17: People were still heading to work at this railway station in Tokyo today, although all of them wearing protective masks

Japan's spike began shortly afterwards. The first jump of more than 100 was on March 25, and the subsequent week saw an average of 159 new cases per day.

The numbers have since risen further, and the Tokyo region alone has recorded more than 200 new infections in the last 24 hours, Abe said. Health ministry figures show a total of 488 new cases in Japan today.

Abe warned against allowing a similar spike during Golden Week, when four public holidays fall within a short period in late April and early May.

Warning that Japan is 'approaching the golden week with an increase in infected cases', he told people not to travel around the country during the holiday week.

'I believe that for this golden week our national income is going to be reduced by 90 per cent,' he said.

'I am sorry for that information but I need a joint effort from all walks of life from all the people in Japan.'

Up to 80 per cent of 'normal business' should be shut down during the virus outbreak, Abe said.

'We should minimise activities in companies and the private sector as much as possible,' he said today.

'We should try hard for our medical workers who are fighting at the forefront of Covid-19.

'We need a joint effort across the whole nation. I believe this infectious disease is creating a very strange, harsh scenario for all the people in our nation.'

People wearing masks walk through a ticket gate at a railway station in Tokyo today

A woman poses with the face masks which have just arrived from Japan Post today after Shinzo Abe ordered two of them sent to every household

Japan now has 8,582 cases while at least 136 people have died, lower figures than in many developed countries but a worse picture than in mid-March.

Japan's record is also less favourable than that of South Korea, which has been widely praised for its mass testing programme and pioneering use of smartphone tracking.

China has also flattened the curve more successfully, if its government figures are to be believed - although there is much scepticism about these.

Japanese authorities were also criticised for their handling of the Diamond Princess cruise ship outbreak and for fighting a losing battle to avoid postponing the Tokyo Olympics.

Abe said today that every Japanese resident would receive a payment of 100,000 yen (£750), saying the government was 'moving quickly to deliver cash to all people'.

An initial offering of 300,000 yen (£2,250) to some households has been abandoned and Abe apologised for the confusion today.

The Japanese economy was heading for recession even before the coronavirus crisis, contracting by 1.8 per cent in the final quarter of last year.

Since then, tourism has dropped by as much as 90 per cent, while industry and trade have ground to a halt.

Last month, Abe unveiled a package of stimulus measures worth around $1 trillion to protect jobs, bolster the medical sector and ease the pain for working families.

The World Health Organization warned today that Japan may have to ramp up its containment measures after clusters were found with no known links to other outbreaks.

'Japan has seen cases of COVID in three prefectures including Tokyo that are not linked to known chains of transmission,' Michael Ryan, executive director of the WHO Health Emergencies Programme told a press conference.

'That is not good, but they are looking. The data I seen this morning reassures me they are very aggressively following this,' he said.

A Japan Post worker loads face masks nicknamed 'Abenomasks' onto a motorbike to distribute them among residents in Tokyo today

Japanese teams of 'cluster busters' have gained some very useful information, including that only one in five infected people spread the disease, Ryan said.

Meanwhile Japan has begun distributing reusable face masks, already dubbed 'Abenomasks' - a play on 'Abenomics', the nickname for the PM's signature economic policies.

The government is issuing two masks per household to ease a nationwide shortage, but the small size of the masks has already attracted ridicule. The Abe masks sit over a much smaller portion of the face than the usual disposable surgical masks.

About 50million households across the country will receive the masks, delivered by Japan Post.

At a post office distribution centre in Tokyo on Friday, the first sets were going out for delivery to parts of the city with the highest number of virus cases.

'We'll be delivering the masks without any physical contact with the customer, just putting them in letter boxes,' said Japan Post official Hideo Aoyama.

'A lot of people are waiting for these masks, so I'll be delivering them as quickly as possible,' added postman Taketo Nishiwaki.

Face masks are not obligatory in Japan but were commonly worn during cold and hay fever seasons even before the coronavirus outbreak.