The European Union is considering shunning Belarus's airspace and banning national carrier Belavia from its airports after Belarusian authorities scrambled a warplane and forced a Ryanair jetliner to land in Minsk to arrest a dissident.
EU leaders strongly condemned Belarus over Sunday's incident, in which a flight from Greece to Lithuania was diverted and Roman Protasevich, an opposition-minded journalist who was on board the plane, was detained.
Three Baltic states - Lithuania, Latvia and Estonia - said Belarusian airspace should be declared "unsafe" and that the 27-nation EU should close its airspace to Belarusian flights. Poland wants to suspend all flights between EU and Belarus until Protasevich walks free.
"I will propose that all flights from Belarus to the European Union and back be stopped until this young man is released," Polish Prime Minister Mateusz Morawiecki said, during a news conference about 26-year-old Protasevich.
A Latvian airline, airBaltic, became the first to announce it would no longer use Belarusian air space, while France and Ireland said air traffic restrictions could be part of the EU's response.
"Together with international partners, we will work to close the airspace of Belarus to international flights," said Lithuanian Prime Minister Ingrida Simonyte.
But it was not immediately clear whether that would amount to a legal ban, who would institute or police it, or what the exact costs would be. A Brussels diplomat said the national EU leaders meeting from 1700 GMT might end up only sending "a political signal" to avoid Belarusian airspace.
French President Emmanuel Macron's Europe minister, Clement Beaune, called the plane's forced diversion "an act of state piracy that cannot be left unpunished", and proposed tougher sanctions against Belarus. Macron's office said the EU might also suspend ground transit links with Belarus.
The summit will likely decide to tighten sanctions already in place against Minsk, where Lukashenko has been in power for 27 years.
The EU has blacklisted 88 individuals and seven companies accused of "repression and intimidation" of people protesting against Lukashenko's victory in a contested presidential election last year. Lukashenko denies election fraud.
The sanctions include a ban on travel to the EU and the freezing of any assets held in the bloc, including by Lukashenko and his son.
"We could extend these sanctions to other officials," Beaune said, suggesting an airspace ban would be "reasonable protective measure because Europeans' lives were put at risk."
The Brussels-based EU executive on Monday summoned the Belarusian ambassador, called for the immediate release of Protasevich and an international investigation into the incident.
The EU has so far trod warily on imposing sanctions on Belarus because of the risk that it would push Lukashenko into even closer ties with Russia.
Any EU sanctions require unanimity and usually take weeks, or longer, to prepare and negotiate between the 27 capitals.
"It's not so easy to calibrate sanctions if you want to spare the population," a senior EU diplomat said on possible new measures against Minsk.