North Korea was conducting live-fire drills on its western coast on Sunday, ccording to the Yonhap news agency, the third consecutive day of military exercises along the contentious maritime border with the South, AFP reported. "N. Korea conducting live-fire drills on western coast: S. Korean military," Yonhap reported. "The North Korean military has been conducting the drills north of the South Korean front-line island of Yeonpyeong since around 4 pm (0700 GMT)," it reported, citing a military source.


It further stated that no North Korean artillery shells had fallen south of the Northern Limit Line (NLL), the de facto maritime boundary in the Yellow Sea, and that no deaths had been recorded.


Residents on the South Korean border island of Yeonpyeong were cautioned to stay indoors on Sunday because to the drills and any potential South Korean responses, according to local officials.


"North Korean gunfire is currently being heard," stated a text message issued to all residents on Sunday afternoon, which local officials confirmed to AFP.


"Troops on Yeonpyeong Island are currently responding, but residents are advised to be careful of outdoor activities," the message further reads. 


North Korea fired artillery rounds in the same region on both Friday and Saturday, near Yeonpyeong and Baengnyeong, two thinly inhabited islands immediately south of the two countries' de facto maritime boundary.


Residents of the two islands were told to flee to shelters on Friday, and ferries were halted during one of the peninsula's most significant military escalations since Pyongyang launched shells at one of the islands in 2010.


North Korean shells landed on both days in a buffer zone established under a 2018 tension-reduction agreement, which fell apart in November when the North launched a spy satellite.


North Korea stated on Friday that its live-fire drills that day had not even had "an indirect effect" on the border islands.


On Sunday, Kim Jong Un's powerful sister rejected Seoul's assertions that Pyongyang fired dozens of artillery rounds near their border on Saturday, calling it a "deceptive operation."