All 37 Lufthansa-operated flights departing from or arriving at the airport in the Bulgarian capital are cancelled on Wednesday due to a strike of the pilots of the German airline.

After a strike on long-haul flights on Tuesday, the pilots' union Vereinigung Cockpit (VC) announced a strike on its short- and medium-haul flights from and to Germany on Wednesday.

The second day of strikes cancelled around 1000 of the 3000 scheduled flights on Wednesday, which is expected to affect 140 000 passengers.

This is the 13th strike of pilots in the past year and a half and is the latest attempt to reverse the plans of the company's management to increase the retirement age and cut privileges.