Travellers from outside the EU are being turned away from airports and borders, after the 27-country bloc imposed a 30-day ban to halt the spread of coronavirus.
A group flying in from Turkey was turned away from Germany's biggest airport in Frankfurt late on Tuesday, DPA news agency reports.
EU leaders agreed that internal borders that have been erected in recent days should come down.
Many Europeans work across borders.
More than 200,000 people have been infected worldwide, according to Johns Hopkins University. Europe has been identified by the WHO as now the "epicentre of the epidemic". Latest figures say more than 3,400 people have died in Europe alone.
