Many thanks to trymmus for sharing three photos of Keanu on instagram. The photos were posted from Vienna, Austria. Two of the photos are of Keanu on the plane and one looks like it was in the airport. Cropped photos below.
Update: Clearly these photos are not of Keanu on a flight leaving Italy so they must have been from his trip to Italy. The first photos of him on the ground in Cessenatico were on September 9, so photos must be from September 8.