South Korea urged North Korea on Monday to halt making military threats as Pyongyang warned of a shelling attack on the South similar to the one it waged in 2010 in response to Seoul's crackdown on illegal fishing near the western sea border.

North Korea on Monday condemned South Korea for its operation with the United Nations Command to repel Chinese fishing boats operating illegally in neutral waters between the two Koreas around the Han River estuary.

"They should stop their reckless military provocations at once, bearing in mind that they may spark off an inescapable retaliatory action from the Korean People's Army like the Yeonpyeong Island shelling incident," the Korean Central News Agency said.

In November 2010, North Korea launched an artillery attack on South Korea's Yeonpyeong Island near the tense maritime border. The attack killed four people, including two civilians, and injured 18 others. Seoul's unification ministry rebuked the North's threats of military actions.

"The government thinks that the North's provocative remarks and threats are not appropriate and do not help the improvement of inter-Korean ties," Park Soo-jin, the deputy spokesperson for the ministry, said in a regular press briefing. "It should immediately put an end to the military threat."

On June 10, South Korea and the UNC conducted their first crackdown on Chinese fishing boats illegally operating in the neutral waters of the Han River estuary. The region is a rich fishing ground that has been left largely untouched since the end of the 1950-53 Korean War.

Chinese fishermen are presumed to have bought the right to operate in the waters on the North Korean side of the sea demarcation line, widely known as the Northern Limit Line, but they often intrude into the South Korean side.

Seoul's defense ministry said that South Korea is keeping close tabs on the possibility that Chinese fishing boats can again enter the estuary region though they have not been detected for 11 straight days.

"There has been no conspicuous movement by the North Korean military," ministry spokesman Moon Sang-gyun told reporters, when asked whether the North is conducting an exercise to carry out underwater attacks in neutral waters. (Yonhap)