(AFP) - The number of coronavirus cases worldwide topped four million as some of the hardest-hit countries readied Sunday to lift lockdown restrictions, despite concerns about a second wave of infections.

Governments around the world are trying to stop the spread of the disease while scrambling for ways to relieve pressure on their economies, which are facing a historic downturn with millions pushed into unemployment.

But with the death toll already past 277,000, nations are keen to avoid second waves of infections that could overwhelm their healthcare systems, with a new cluster of cases in South Korea raising fears about the virus hitting back rapidly.

Amid the barrage of deaths, some European countries have cited signs of progress that they said justified cautious steps towards a sense of normality.

Officials in France on Saturday said the day's death toll of 80 was the lowest since early April, while nursing home fatalities also fell sharply as the nation prepared to relax curbs on public movement imposed eight weeks ago.

The easing, to begin Monday, has brought mixed reactions.

"I've been scared to death" about the reopening, said Maya Flandin, a bookshop manager from Lyon. "It's a big responsibility to have to protect my staff and my customers."

French health officials have warned that "the epidemic remains active and is evolving", and that social distancing must be kept up even as restrictions are eased.

In Spain, about half the population will be allowed out on Monday for limited socialisation, and restaurants will be able to offer some outdoor service as the country begins a phased transition set to last through June.

Fears lingered, however, of a resurgence, and authorities excluded Madrid and Barcelona -- two COVID-19 hotspots -- from the first phase.

Belgium is also easing some restrictions on Monday, and in some parts of Germany, bars and restaurants reopened on Saturday with further easing set for Monday.

Overall, the situation in Europe was still far from normal.

Britain is reportedly planning to announce on Sunday that all overseas visitors will face a mandatory two-week quarantine, and the European Union warned against opening borders to travellers from outside the bloc.

Across Europe, commemorations marking 75 years since Nazi Germany's surrender were cancelled or scaled down.

And Poland's election on Sunday will be one for the history books as polling stations remain closed and turnout will clock in at zero due to a political crisis set off by the pandemic -- the presidential ballot is formally neither postponed nor cancelled because the government and opposition were unable to agree on a constitutional and safe solution.

- 'Phenomenal' recovery? -

South Korea's capital Seoul shut all bars and clubs on Saturday after a burst of cases were tracked to one of the city's busiest nightlife districts.

Even as the country eased virus restrictions, officials warned against carelessness after the new cluster of infections, highlighting the challenge of containing the spread of the deadly disease while pursuing an economic revival.

Global economic figures are pointing to the most acute downturn in nearly a century with businesses forced to shut and supply lines badly disrupted, and pressure is growing on leaders around the world to find a way out.

In the United States, the country with the world's highest death toll, President Donald Trump faced sharp criticism from his predecessor Barack Obama, who said on a leaked tape that Trump's handling of the crisis was an "absolute chaotic disaster".

Facing re-election in November, Trump has insisted that next year would be "phenomenal" for the US economy, urging reopening in a country where the virus continues to claim well over 1,000 lives daily.

The United States lost an unprecedented 20.5 million jobs in April, driving the unemployment rate to 14.7 percent -- the highest level since the Great Depression.

- 'Life costs money' -

Health experts have cautioned that while the growth of cases may be slowing in some European and Asian countries, other nations -- many of them impoverished -- are only in the first phases of their outbreaks.

In Iran, the Middle East's virus epicentre, many were taking advantage of loosened restrictions despite worries about a spike in infections.

"Life costs money," said Hamed, a 22-year-old out on the streets of the capital Tehran without a mask. "People have to go to work since this virus has been with us for about three months now."

And in neighbouring Pakistan, the world's fifth most-populous country, the government ended the lockdown on Saturday and locals streamed into markets and shops, despite still-high infection rates.

Tehmina Sattar, shopping with her sister and sons in Rawalpindi, said: "We are happy with this decision, but at the same time I have a fear in my heart that if this disease spreads it could be devastating."

© Agence France-Presse