BEIJING - An aircraft of the Republic of Korea (ROK) flying from Seoul to San Francisco crashed on Saturday, which killed two Chinese. On board, there are 291 passengers, including 141 Chinese, 77 S Koreans and 61 Americans.

People can't help wondering why there are so many Chinese passengers on a Korean airline?

For a long time, through making Seoul into an international hub, ROK has been making efforts to attract Chinese transit passengers by low ticket prices and attractive transit visa-free policy, China Business News, a Chinese newspaper, reported.

According to the investigation of the newspaper, many Chinese passengers on the crashed plane of Asiana Airlines Inc, ROK's No 2 flag carrier, firstly flied from Shanghai to Seoul, and then to San Francisco.

"Of the flights between China and US, the ticket prices of transit flight of ROK airlines are far more cheaper than prices of non-stop flight of Chinese and American airlines. So a lot of Chinese passengers who fly to America prefer to choosing ROK as a transit center." an aviation insider told the media on condition of anonymity.

According to Ctrip, the largest air-ticketing agency in China, there are only China Eastern , Air China Ltd and United Airlines that have non-stop flight from Shanghai to San Francisco. And their ticket prices are more expensive than Asiana Airlines.

The lowest ticket price of direct flight is 8,810 yuan ($1,437, free of tax) from Shanghai to San Francisco on July 15. The most expensive price is almost 20,000 yuan ($3,262). But the transit flight price of Asiana Airlines is only 5,100 yuan ($832).

Similarly, the lowest ticket price of non-stop flight is 8810 yuan ($1,437)on August 7. And the price of Asiana Airlines is 6,560 yuan ($1,070), at least 2,250 yuan ($367)less.

It's worth noting that the ROK government gives supports to build international hubs from a variety of policies. From May 1, International passengers from the 107 listed countries transferring in Seoul are granted 30-day visa-free transit stay.

However in Shanghai, international passengers only enjoy 72-hour visa-free transit stay and the listed countries are 45.