The number of people coming in and out of South Korea on international flights rose 4.2 percent on-year in the first half as a growing number of South Koreans are going abroad for vacation, the government said Tuesday. The number of international flight passengers to and from South Korea reached 19.95 million in the first six months of the year, up from 19.15 million in the same period last year, according to the Ministry of Land, Transportation and Maritime Affairs. Passenger traffic within most regions rose with an increase in South Koreans going abroad as well as the number of people coming to South Korea for vacation, the ministry said. Passengers to and from Southeast Asian countries jumped 17.7 percent from a year earlier to over 6.5 million with travelers going to and from China also surging 5.5 percent to over 4.5 million. Passengers to and from Japan, however, dropped 12.7 percent on-year apparently due to effects of the March 11 earthquake and tsunami that crippled a Japanese nuclear power plant. The crisis at the plant lead to a radiation scare in Japan as well as South Korea. Of the total, 65.7 percent of all international passengers used flights offered by South Korea\'s two flagship carriers, Korean Air Co. and Asiana Airlines Inc., with the percentage of people using flights by the country\'s low-cost carriers doubling from 1.8 percent last year to 3.6 percent. The rest used services from foreign airline companies. Gains by South Korea\'s five budget carriers were also seen in the domestic market where the number of domestic passengers using low-cost flights grew over 20 percent on-year to 4.07 million while the total number of people using domestic flights only inched up 0.7 percent to 10.05 million. \"In addition, the combined market share of low-cost carriers for the Gimpo-Jeju route rose 27.4 percent from the same period last year to 52.8 percent, surpassing the 50 percent mark for the first time in history,\" the ministry said. Despite gains in international and domestic flight services, air cargo traffic dropped 2.4 percent on-year to 1.74 million tons in the first half of the year due to high fuel prices, the ministry said.