People watch a TV report at Seoul Station about North Korea's firing of artillery shots, Oct. 19. Yonhap

North Korea fired around 100 additional artillery shells into waters off its west coast Wednesday, South Korea's military said, following its overnight launch of artillery rounds.

The Joint Chiefs of Staff (JCS) said it detected the shells lobbed into the Yellow Sea from Yonan County, South Hwanghae Province, starting at 12:30 p.m.

The shells landed in the western buffer zone set under an inter-Korean military agreement signed on Sept. 19, 2018, to reduce border tensions, according to the JCS. None of them fell into South Korean waters.

"Our military communicated a warning multiple times, regarding (the North's) breach of the Sept. 19 military accord and the immediate cessation of provocations," the JCS said in a text message sent to reporters.