At least 8,248 people have died and 205,452 people have been infected worldwide, according to Johns Hopkins University. Europe has been identified by the WHO as the “epicentre of the epidemic”.
People have been urged to stay at home as much as possible and only essential travel will be allowed. Most shops will close, but physical activity is allowed as long as people respect social distancing.
In another blow to the continent’s normal life, the Eurovision Song Contest has been cancelled. The 64-year-old event, which has a big global following, was due to take place in the Dutch city of Rotterdam in May.
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The ban specifically covers all EU states as well as countries within the Schengen border-free zone, including Iceland, Switzerland, Norway and Liechtenstein.
All citizens will be given help returning home, and Germany on Wednesday said it would continue a drive to fly home tens of thousands of tourists stranded abroad, from Morocco and Egypt to the Philippines and Argentina.
The Robert Koch Institute (RKI), the scientific body advising the government on health issues, has warned that Germany could see up to 10 million cases of coronavirus infections within the next two to three months unless the current containment measures are strictly followed.
“It is absolutely crucial that we unblock the situation, because we know that too many people are stranded within the European Union and have a problem to go back home,” said European Commission President Ursula von der Leyen.
Long queues on Polish border
By Adam Easton, BBC News Warsaw
Trucks are stuck in a long traffic jam on a road in Germany about 50km from the Polish border
Some people are having to wait for more than 24 hours following the introduction of checks at midnight on Saturday.
Foreigners are temporarily banned from entering the country and returning Polish citizens must be quarantined for 14 days. Border guards wearing protective suits and face masks are taking the temperature of everyone crossing the border.
At the crossing in Jedrzychowice on the German border on Wednesday morning, people have been stuck in their vehicles overnight, many with nothing to eat or drink and with no access to toilets.
How bad is the situation in Europe?
In the UK, the number of dead has reached 104.
Germany has 12 deaths and 8,198 cases. Chancellor Merkel is to make the unusual step of speaking to the nation in a TV address later on Wednesday. She is not expected to announce new measures, but rather appeal to citizens to help fight the virus.
Belgium has 14 deaths and 1,486 cases
The governor of the northern Lombardy region, Attilio Fontana, has begged people to stay at home. The numbers were so high, he said, that “soon we’ll be unable to respond to people who fall ill”. “We are asking you for a sacrifice to save human life.”
What else did the Commission leader say?
Mrs von der Leyen told reporters on Tuesday that she hoped a vaccine could be available by autumn. Her are out of step with health officials elsewhere, but she said there were means to speed up bureaucratic processes that were normally slow and difficult.
She accepted it was a “worrying enemy” but said she did not see the fight against it as a war. Measures that sounded “drastic, draconian” two weeks ago, she said, were now accepted as necessary.