SOFIA, March 21 (Xinhua) -- Bulgaria's airports have served nearly 11.5 million passengers in 2017, a 24-percent increase year on year, according to a report presented here on Wednesday.

Svetoslav Stanulov, Chairman of the Bulgarian Airlines Association, who presented the report at a press conference, attributed this significant growth to the regular international flights from and to Sofia, and the increase of low-cost airlines.

Last year, nearly 6.5 million passengers passed through Sofia Airport, a 34.9-percent increase compared to 2016, the report said.

Among them, the number of passengers on scheduled international flights rose by 29.1 percent to nearly 6.1 million, the report said.

The Black Sea airports Burgas and Varna served close to 3 million passengers and nearly 2 million passengers respectively.