The Democratic People's Republic of Korea (DPRK) on Monday fired more than 100 artillery shells into waters off the west coast of the Korean Peninsula, the South Korean Ministry of National Defense confirmed to Xinhua.

The DPRK fired about 10 rounds of artillery into waters near the South Korean island of Baekryeongdo off the west coast around 17:30 local time Monday, and fired near 100 artillery shells into waters near the island of YeonPyeongdo during the period from 17: 52 to 18:14 local time the same day, the ministry's press office said.

Both areas are near the contentious sea border called the Northern Limit Line (NLL).

Given that all the shells dropped into waters north of the NLL, and did not cause any damage to the South side, the South Korean military only sent warning messages without firing warning shots in response to the DPRK's shootings, and has been keeping an eye on further moves by the DPRK, the ministry said.

The artillery firing came as South Korea's five-day military drill in the Yellow Sea, which took the DPRK as the simulated enemy, entered the final day.

The DPRK warned last week that it would take a military " physical counterattack" against the Seoul's exercise.

The NLL was fixed unilaterally by the U.S.-led United Nations Command after the 1950-1953 Korean War. South Korea holds the NLL as the de-facto western inter-Korean border, but the DPRK rejected the NLL and only recognized the demarcation line it drew in 1999, which was further south of the NLL.