At least two European airlines cancelled flights to Moscow after Russian aviation authorities refused to give them permission to change their routes and bypass Belarus airspace.
Air France cancelled a flight from Paris on Thursday after it was delayed the previous day, and later announced that Friday’s flight had been grounded as well.
Austrian Airlines said it cancelled a flight from Vienna after Russian authorities denied approval of adjustments to its route that would allow the plane to avoid flying over Belarus, spokeswoman Yvonne Wachholder said.
Austria’s Foreign Ministry called the Russian move “totally incomprehensible” and asked Moscow for an explanation.
EU airlines were this week urged by Brussels to avoid airspace over Belarus after the forced landing in Minsk on Sunday of a Ryanair plane flying from Greece to Lithuania with a dissident Belarusian journalist on board.
Roman Protasevich and his girlfriend, Sofia Sopega, were arrested after landing.
Air France has not had any other problems on flights bypassing Belarusian airspace and flying over Russia, which is a strong ally of Minsk.
Russian President Vladimir Putin was scheduled to meet his Belarusian counterpart Alexander Lukashenko in the Russian city of Sochi on Friday amid an international outcry over the diversion of the Ryanair flight and the arrests.
Foreign affairs ministers of G7 countries and the EU condemned the actions of Mr Lukashenko's government.
“This action jeopardised the safety of the passengers and crew of the flight. It was also a serious attack on the rules governing civil aviation,” they said.
“This action also represents a serious attack on media freedom.
"We demand the immediate and unconditional release of Roman Protasevich, as well as all other journalists and political prisoners held in Belarus.”
The parents of both detainees pleaded for the release of their children.
Anna Dudich, the mother of Ms Sapega, was close to tears when she spoke.
"We are in such a state that we don't believe this is happening to us, to our daughter," Ms Dudich said.
"I'm ready to beg anyone for help so my child's life isn't broken.
"I don't understand why my daughter was detained. She's just living her life like a normal young woman – studying, having fun and in love.
"No one banned that, did they? I just can't get my head around it."
Mr Protasevich’s parents pleaded for help in securing their son’s release.
"I want to appeal to you as Roman's mother," Natalia Protasevich said.
"I want you to hear my cry, the cry of my soul, so that you can understand how difficult it is for us right now and how we have found ourselves in an absurd situation.
"I want you to relay our appeal everywhere, throughout the world, to government representatives, to EU countries, to EU leaders, to US leaders.
"I am appealing, I am begging: help me free my son."
His father, Dmitry, described his son as a hero who “has fought for truth” throughout his life.
EU foreign ministers are meeting in Lisbon as they consider imposing sanctions on Belarus.
Luxembourg's Foreign Minister Jean Asselborn said the bloc could focus on Belarusian exports of potash, also known as fertiliser potassium.
"The hijacking of the plane and the detention of the two passengers is completely unacceptable, and we will start discussing implementation of the sectorial and economic sanctions," EU foreign policy chief Josep Borrell said.