A total of 5.7 million passengers passed through Greek airports during the first three months of the year, up 16.9 percent compared to the same period in 2015, which had handled 4.9 million passengers, according to data released on Tuesday by the Civil Aviation Authority.

Works are set to get under way across the network of 14 regional airports that Frankfurt-based transport company Fraport took over late last year in a privatization deal that brought a total of 1.2 billion euros to Greek state coffers.