Story highlights North Korea makes 'sea of fire' threat after South Korea holds exercises

The South stages one-year anniversary exercises near Yeonpyeong Island

A year ago, the North shelled the island, killing two marines and two civilians

One day after South Korea staged exercises near Yeonpyeong Island marking the anniversary of North Korea's deadly shelling, the North's military threatened "a sea of fire" upon the South's presidential office, the South's Yonhap News Agency reported Thursday.

A year ago Wednesday, North Korea launched an attack on the civilian island of Yeonpyeong, killing two marines and two civilians and shattering the sense of security that South Koreans had enjoyed for almost 60 years.

The island shelling came half a year after North Korea torpedoed a naval ship, the Cheonan, killing 46 sailors.

North Korea's military supreme command denounced the South's anniversary exercise as a rehearsal for war against the North and warned that the North's armed forces are ready for "a decisive battle to counter any military provocation," Yonhap reported.

If South Korea dares "to impair the dignity of (the North) again and fire one bullet or shell toward its inviolable territorial waters, sky and land, the deluge of fire on Yonphyong Island will lead to that in Chongwadae and the sea of fire in Chongwadae to the deluge of fire sweeping away the stronghold of the group of traitors," the command said in an official (North) Korean Central News Agency account, according to Yonhap.

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The North Korean statement used a different spelling for both the shelled South Korean island and Cheong Wa Dae, Korea's presidential offices, Yonhap reported.

South Korea's defense ministry had no immediate comment, Yonhap reported.

North Korea invoked identical rhetoric in 1994, when Pyongyang had expelled international nuclear inspectors and threatened to turn Seoul into a "sea of fire."

With the United States mulling air strikes on North Korean facilities in 1994, former U.S. President Jimmy Carter flew into Pyongyang to meet Kim Il Sung, and that set the scene for the so-called "Agreed Framework" under which North Korea would give up its nuclear facilities in return for light water reactors from the international community.