Finland's national airline Finnair has said its planes will avoid Belarusian airspace until further notice.
The first re-routed flight is scheduled to leave Helsinki for Gazipasa in Turkey on Wednesday. Finnair said the diversion will increase the flight time.
Finnair's statement comes after a Ryanair passenger plane was forced to land in Minsk on Sunday so that KGB officers could arrest opposition activist Roman Protasevich.
An EU summit on Monday called on airlines flying to EU countries to avoid Belarussian airspace, and several airlines have already announced that they will do so.
An estimated 2,500 flights a week pass through Belarusian airspace, according to the European Organisation for the Safety of Air Navigation, commonly known as Eurocontrol.
The Ryanair flight had been en route from Athens in Greece to Vilnius in Lithuania.