Some South Koreans have recently held anti-Pyongyang events in Seoul.
One of the messages claimed that Seoul's insult to the North is a provocation by conservative forces to win the presidential election in December, according to the official who is familiar with the issue.
President Lee Myung-bak's single five-year term ends early next year and by law, he cannot seek re-election. North Korea has repeatedly condemned Lee as a traitor and called for his ouster in an apparent protest of his hard-line policy toward Pyongyang.
