LHASA, Dec. 14 (Xinhua) -- The annual passenger throughput of Gonggar Airport in southwest China's Tibet Autonomous Region surpassed 3.5 million on Dec. 6, according to the region's civil aviation authorities.

It marked an increase of nearly 11 percent year on year.

The steadily growing tourist arrivals in Tibet were attributed to the region's rapid economic and social development in recent years, said an official with the regional bureau of the Civil Aviation Administration of China.

The annual passenger volume of Gonggar Airport, which opened in 1965, surpassed one million in 2006, two million in 2013 and three million in 2016.

The regional capital Lhasa has started expansion on the airport. By 2025, Gonggar airport will be expected to handle nine million passenger trips annually.

Currently, Tibet has five airports and is linked by 74 air routes to 41 cities.