North Korea fires more than 130 shells in nighttime military exercises

SEOUL, May 14 (UPI) -- North Korea engaged in an artillery firing drill on Wednesday and again on Thursday, firing more than 130 shells into the Yellow Sea.

The shelling occurred a mere 7.5 miles northwest of South Korea's Yeonpyeong Island, which fell under North Korea attack in 2010, Yonhap reported.

That attack led to the death of four South Koreans.

Wednesday's shelling took place from 9 to 10:25 p.m. local time. South Korean newspaper Maeil Business reported the late-night firing exercise was an unusual move, and was probably a drill to improve North Korea's night-operations capability.

South Korea's joint chiefs of staff said prior to the artillery exercise that North Korea sent Seoul a preliminary statement on its plan to engage in "practice drills." The drills, the statement read, would last from Wednesday into Friday.

The shells landed in waters just north of the Northern Limit Line, or NLL that marks the boundaries of North and South Korea at sea. No shell landed on the South Korean side.

The drills, however, have placed Seoul's Defense Ministry on high alert.

"North Korea's latest maritime firing is a clear act of tension escalation on the northern side of the NLL, and our military is standing in all-out military reaction position with a keen eye upon the movement of the North Korean military," the South Korean joint chiefs said Wednesday.

On May 8, North Korea claimed South Korean naval boats in the Yellow Sea had repeatedly entered territorial waters belonging to North Korea.

North Korea will fire at future trespassers, stated KCNA, adding North Korean leader Kim Jong Un authorized the warning.