Non-European Union citizens have been turned away from a German airport after Brussels imposed an entry ban on travellers from outside the bloc for 30 days to battle the spread of coronavirus.
Around 140 people are believed to be have been told to turn back at Frankfurt Airport.
"It could be the case that there are 20 or 30 passengers on board a plane that will need to directly fly back on the same plane," Reza Ahmari of the German police told Hessische Rundfunk.
The move by the EU is its most significant emergency measure yet, which has rushed to devise a unified response to the deadly pandemic spreading quickly across the continent.
There are approximately 80,000 EU nationals around the world waiting to return home, a spokesperson said.
The 27 leaders spoke on a video conference to agree to the ban on non-essential travel to the EU, an idea strongly supported by France.
European Commission President Ursula von der Leyen proposed that the bloc’s Schengen passport-free zone impose the measure and that fellow EU states outside it follow suit.
And in a sombre address to the nation on Monday, French President Emmanuel Macron supported the move.
The ban will be in effect for an initial 30 days and will not affect Europeans returning home, social workers, cross-border workers or citizens of former EU member Britain.
“This is an exceptional measure that shouldn’t last longer than necessary,” Sweden’s Minister for Home Affairs, Mikael Damberg, said in Stockholm.
German Chancellor Angela Merkel is expected to address the national on Wednesay night.
The EU’s leaders hoped to persuade member states that they need not close doors to one another as some have unilaterally adopted various policies to slow the rapid surge of coronavirus in Europe.
After the talks, Mr Macron’s office said he “firmly condemned unco-ordinated measures to control internal EU borders that are not helpful in terms of health and hurt the economy”.
Several EU countries have closed their frontiers or imposed health screening controls that slow cross-border freight traffic, despite calls from Brussels for a single European plan.
Italy, Spain, France and now Belgium have opted for widespread lockdowns, ordering citizens to stay at home for all but essential trips.
The Netherlands has taken a looser stance, hoping to build collective immunity.
Britain also began trying to build herd immunity, but backtracked on its plan and instead switched to stricter measures.
Prime Minister Boris Johnson has advised everyone to avoid social spaces such as theatres, nightclubs and concerts.
As the lockdown in France loomed, people in Paris fled the city. It has led to concerns that the health systems in areas neighbouring the capital could come under increased pressure.
Josiane Chevalier, an official for Grand Est and Bas-Rhin in northeastern France, told local radio: “We have a large number of infected people, which continues to rise every day."
He also said groups vulnerable to the virus would be asked to isolate themselves for at least 12 weeks.
Italian Prime Minister Giuseppe Conte on Tuesday declared that the coronavirus was causing a “socio-economic tsunami” as European leaders agreed to seal external borders.
He said no nation would be “untouched by the tsunami” and called for special “coronavirus bonds”, or a European guarantee fund, to help member states finance urgent health and economic policies, an Italian government source said.
Ms von der Leyen said: “The enemy is the virus and now we have to do our utmost to protect our people and protect our economies.
“We are ready to do everything that is required. We will not hesitate to take additional measures as the situation evolves.”