Russia received the official notification from Bulgaria, Poland and the Czech Republic regarding the closure of their airspace, a source in a Russian air carrier told TASS, adding that Russia is planning its further actions.

"Bulgaria, Poland and Czechia sent a NOTAM [air traffic prohibition notification], we are evaluating [our further actions - TASS]," he said.

Previously, the media reported that Bulgaria, Poland and the Czech Republic are closing their airspace for Russian aircraft starting on Saturday. The UK also closed its airspace; in response, Russia closed its own airspace for British plane, including for transit flights.