Passengers line up to check in at the Austrian Airlines counter at Vienna International Airport in Vienna, Austria, June 15, 2020. Austrian Airlines partially resumed operation on Monday. (Photos: Xinhua)

Passengers check in at the Austrian Airlines counter at Vienna International Airport in Vienna, Austria, June 15, 2020. Austrian Airlines partially resumed operation on Monday.

The aircrafts of Austrian Airlines dock at Vienna International Airport in Vienna, Austria, June 15, 2020. Austrian Airlines partially resumed operation on Monday.

Passengers line up to check in at the Austrian Airlines counter at Vienna International Airport in Vienna, Austria, June 15, 2020. Austrian Airlines partially resumed operation on Monday.