A coastal town in North Korea's Hwanghae Province is seen from an observatory on Yeonpyeong Island, a South Korean border island in the Yellow Sea, Jan. 6. Yonhap

North Korea fired some 90 artillery shots into waters off its western coast Sunday, South Korea's military said, the latest in a series of drills near the tensely guarded western border.

The Joint Chiefs of Staff (JCS) said it detected the artillery firings into the waters north of Northern Limit Line, a de-facto maritime border in the Yellow Sea, and South Korea's border island of Yeonpyeong from about 4 p.m. to 5:10 p.m.

There was no damage to the South Korean military or civilians from the latest firing, according to a JCS official.

Earlier in the day, Ongjin County, which has jurisdiction over South Korea's northwestern border islands, issued a warning to the islands as artillery fire was heard from the North Korean side.

"Troops on Yeonpyeong Island are currently responding, but residents are advised to be cautious of outdoor activities," the county said in a text message sent to islanders.

It marked the third consecutive day of North Korean artillery drills in the area, the South's military said, raising tension near the maritime border.

On Friday, North Korea fired some 200 artillery shells from its southwestern coastal areas, prompting the South Korean troops on the front-line islands of Yeonpyeong and Baengnyeong to stage live-fire drills in response.

North Korea's Friday artillery firing marked the 16th one of its kind, including a missile launch in December 2022. The South Korean military conducted live-fire drills near the maritime buffer zone for the first time since the signing of the 2018 pact.

The latest saber-rattling came after Pyongyang in November vowed to restore military measures halted under a 2018 inter-Korean military agreement, which set up buffer zones in land, sea and air, and banned live-fire drills near the border area to prevent accidental clashes.

On Saturday, the North carried out live-fire drills for the second consecutive day to fire around 60 shells from the western coast, the Joint Chiefs of Staff said.

Earlier in the day, Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, claimed the North conducted a "deceptive operation" by detonating explosives simulating the sound of 130 mm coastal artillery the previous day, deriding the South Korean military's detection capabilities.

The JCS dismissed the statement, calling it "comedic low-grade" propaganda attempting to cause division within South Korea and damage trust in the military.

"Kim Yo-jong appears to have announced a false statement as (she) was surprised by our military's detection capabilities," the JCS official said. "North Korea's artillery firing (on Saturday) was also detected by our military's detection assets." (Yonhap)