TOKYO, Aug 9 (Saba) -- North Korea fired some 110 rounds of artillery Monday into its side of a disputed maritime border with South Korea, Yonhap News Agency reported, citing South Korean military officials.

North Korea first fired some 10 shells over three minutes starting at around 5:30 p.m. (0830 GMT), said an official at the South's Joint Chiefs of Staff, according to the report. The gunners then fired about 100 rounds between 5:52 p.m. (0852 GMT) and 6:14 p.m. (0914 GMT), he said.

The rounds all landed into the North Korean side of the so-called Northern Limit Line (NLL) that has served as a de facto border in the Yellow Sea. "The Navy heightened its readiness posture" in the wake of the artillery firing, the official said, adding that there has been no North Korean firing afterwards.

The North Korean move comes right after South Korea ended a five-day navy massive naval exercise near the Yellow Sea border in a show of force against its communist neighbor that it blamed for sinking one of its warships in March that killed 46 sailors.

Sorth Korea had warned of "strong physical retaliation" against the drills which it denounced as preparations for a northward invasion.

The NLL was drawn by the United Nations at the end of the 1950-53 Korean War. North Korea has never recognized it, making it a constant source of military tension between the two Koreas. The area is the scene of bloody gunbattles between the navies of the two Koreas in 1999, 2002 and most recently in November last year.

South and North Korea are still technically at war, with no peace treaty signed at the end of the 1950-53 Korean War.

Saba