DALIAN, Dec. 6 (Xinhua) -- China's first international high capacity civil air corridor was put into service on Thursday to help ease flight congestion between China and the Republic of Korea (ROK), according to the Civil Aviation Administration of China (CAAC).

The optimization separates flights entering and leaving ROK that used to congest the airway before.

With the new air corridor, the air domain for civil aviation above the Bohai Bay between China and the ROK is expected to increase flight capacity by 45 percent and reduce flight safety risk by 42 percent, according to CAAC.

"The high capacity air route will alleviate air traffic congestion in the old air route and facilitate logistics between the ROK and China," said Kim Sangdo, director general of the Office of Civil Aviation Safety Policy at the Ministry of Land, Infrastructure and Transport, ROK.

Flight KL856 from the ROK to the Netherlands on Thursday became the first to use the new airway.