Fireworks have lit up skies across Japan in surprise displays to lift spirits during the Covid-19 pandemic.

The shows were held at secret locations, each lasting five minutes from 20:00 local time (12:00 BST).

Organisers set a time limit for the displays to avoid crowds gathering.

Initially, they said the time and date of the event would not be revealed but later reversed course, deciding a sudden pyrotechnics show could cause distress to some.

Filling the skies with a burst of light, the fireworks lasted long enough for people who did not know about it in advance to view them from the street or their homes.

Yet, the fireworks still drew modest crowds in places. In the capital Tokyo, people were seen watching the displays near the Tama River, before dispersing when they were over.

“I had a hunch, so I came here,” one of the spectators, Yukiji Kushiro, told Japanese newspaper the Mainichi Shimbun. “Even though they say it’s a secret, there are only so many places they can launch fireworks.”

Dozens of firework-makers nationwide were involved in organising the synchronised displays, a project called “Cheer up Hanabi”.

They are struggling to keep their businesses afloat because many traditional festivals have been cancelled or postponed due to the pandemic.

The postponement of the Tokyo 2020 Olympics was a major blow for the industry, leaving craftsmen unable to sell fireworks they had spent months making.

One of the craftsmen, 38-year-old Kouhei Ogatsu, said the pyrotechnics industry had been discussing ways to cheer up a society “changed so much by the coronavirus”.

“Historically fireworks in Japan have been launched to pray for the eradication of plagues and to console the spirits of the deceased,” he told the AFP news agency.

Written messages praying for the end of the pandemic were attached to some of Mr Ogsatu’s fireworks.

His company launched nearly 100 fireworks from four locations across eastern Japan.”Of course I don’t think the coronavirus will disappear with our fireworks. But we wanted to do this and hope something good will come out of it,” he said.

Last month, Japan lifted its state of emergency after a marked fall in new coronavirus cases.

Prime Minister Shinzo Abe urged people to “remain vigilant” and adopt a “new lifestyle” to prevent a second wave of infections.

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Japan faced early criticism for its handling of the virus, but appears now to have avoided a epidemic on the scale of that seen in the US, Russia or the UK.

The country has recorded 16,787 infections and 899 deaths so far, according to a tally by Johns Hopkins University.