South Korea's foreign ministry on Monday warned of the potential dangers that could be faced when visiting Chinese areas bordering North Korea."There are possibilities that North Korea may kidnap or even commit terror against South Korean nationals near the China-North Korea border, including Mount Baekdu."North Korea has threatened retaliation against Seoul if it does not send back a group of 13 North Korean restaurant workers who defected South in early April.Pyongyang has repeatedly called for their repatriation.In light of such threats, Seoul's foreign ministry urged travel agencies to be extra careful when selling tour packages to related Chinese border cities."When South Korean travel agencies sell China travel packages to South Korean citizens, they must explain the dangers of visiting border areas near North Korea, and even suggest travelers not to visit those places."Seoul's government has also warned South Korean missionaries and the press to avoid visiting border regions for personal safety.South Korean embassies abroad are also warning citizens who go overseas to take extra precaution regarding possible threats from the North, through mobile phone text messages.Ji Myung-kil, Arirang News.