The head of South Korea's rail operator left for China on Monday to attend an international rail conference to be held in Pyongyang. Choi Yeon-hye, president and CEO of the Korea Railroad Corp., and four other officials plan to travel to North Korea from Beijing to attend a meeting of the Organization for Co-Operation between Railways (OSJD) set for April 24-28. There are no direct flights between the two rival Koreas, which are still technically at war since the 1950-53 Korean War ended in a truce, not a peace treaty. "It would be better notto place any special meaning" on her trip to Pyongyang as it is designed to attend a meeting of OSJD, Choi said before leaving for China. The organization said on its website that it is composed of 27 members states, including China and Russia, and its main objectives include development of international freight and passenger traffic and creation of common railway transport environment in the Eurasian region. The visit comes as tensions are still high on the Korean Peninsula after North Korea fired a series of missiles and rockets off its east coast and threatened to conduct a "new form of nuclear test."    South Korea has long talked about linking its rail system with Russia's trans-Siberian railway via North Korea, though the project has made little progress due to political and security tensions in the region. Yeongjong Island is home to Incheon International Airport, South Korea's main gateway.