North Korea denies firing near border with South (UPDATE)

North Korea denies it fired artillery rounds into the Yellow Sea on Wednesday, saying what South Korean military personnel heard was actually construction blasting inside North Korea.

South Korea’s military on Wednesday said it fired three artillery rounds at the sea border with North Korea after hearing explosions coming from the area of Yeonpyeong Island, scene of an attack by the North's forces last November that killed four.

A defense official quoted by Bloomberg said the military wasn’t aware of any drills in the area. And military officials in the South were not accepting the North's explanation Thursday, VOA reports.

Meanwhile, South Korean news outlets were reporting that North Korea was plotting to kill the South's defense minister because of his hardline stance against the communist regime.

The outlets reportedly said that South Korean intelligence has received reports that a team — possibly foreigners working on Pyongyang's orders — has been sent to assassinate Kim Kwan-jin, VOA reports.

No injuries were reported in the shellfire Wednesday, which occurred when, according to the Wall Street Journal, "three shots were heard coming from the North Korean island of Youngmae and one shell crossed the Northern Limit Line that divides the two countries in the Yellow Sea."

The South Korean navy sent a warning broadcast to the North soon after the shots were heard, and fired back three shots at the North, Commodore Jung Jin-seok of the Joint Chiefs of Staff said. There was no subsequent response from the North.

The Northern Limit Line has been a source of repeated conflict since their 1950-1953 civil war ended in a cease-fire.

A month ago, both nations were ready to revive multilateral talks on the North’s nuclear weapons program, signaling an easing of tension between them.