Germany reported on Monday that new coronavirus infections were accelerating exponentially after early steps to ease its lockdown, news that sounded a global alarm even as businesses opened from Paris hair salons to Shanghai Disneyland.

Germany's Robert Koch Institute reported that the “reproduction rate” - the number of people each person infected with the coronavirus goes on to infect - had risen to 1.1. Any rate above 1 means the virus is spreading exponentially.

German authorities had taken early steps to ease lockdown measures just days earlier, a stark illustration that progress can swiftly be reversed even in a country with one of the best records in Europe of containing the virus so far.

It follows a new outbreak in night clubs in South Korea, another country that had succeeded in limiting infections.

Governments around the world are struggling with the question of how to reopen their economies while still containing the coronavirus. In Europe, the world's worst-hit continent, Spain and France began major steps to ease lockdowns, while Britain announced more cautious moves.

A German health ministry spokesman said the authorities were taking the rise in the infection rate seriously and it did not mean the outbreak was out of control.

New Zealand, which had success in fighting infection with one of the toughest and earliest lockdowns, said it would open malls, cafes and cinemas this week.

India, which has locked down its population of 1.3 billion people since March, reported a record daily rise in cases. But it said it would begin to restart passenger railway services, with 15 special trains, from Tuesday.

Russia, where the death toll is still comparatively low but the caseload surging, overtook Italy and Britain to report the highest number of cases after the United States and Spain.

In the United States, where unemployment figures released last week were the worst since the Great Depression, President Donald Trump has been trying to shift the emphasis towards reopening the economy. Many states have begun loosening restrictions even though cases continue to rise.