North Korea has threatened to strike South Korea in response to conservatives' anti-Pyongyang rallies in Seoul on the second anniversary ofleader Kim Jong-il's death earlier this week, a senior military official said, according to Yonhap News.

On Thursday, North Korea's National Defense Commission threatened to strike the South "without notice" via a fax sent to South Korea's National Security Council through the western coastal military hotline, the official noted. The threat comes after several conservative groups and North Korean defectors held rallies in Seoul to protest North Korea's authoritarian rule and human rights abuses. Some protesters burned Kim Jong-un's photo, Yonhap News reported.