This photo, released in March 2020 by North Korea's official Korean Central Television, shows the country's artillery units firing shells. Yonhap

North Korea fired a barrage of artillery shells into a maritime buffer zone for a second consecutive day Tuesday in response to live-fire drills between South Korea and the United States.

South Korea's Joint Chiefs of Staff (JCS) said the North fired about 90 artillery rounds from 10 a.m. through the afternoon from Kosong County in Kangwon Province toward the East Sea. About 10 more firings were detected after 6 p.m. from Kumgang County in the same province, the JSC said.

The shells splashed into the maritime buffer zone north of the Northern Limit Line, a de facto sea border, in violation of the 2018 inter-Korean military accord to reduce border tensions, the JSC added.

North Korea confirmed the firings later in the day, saying it launched 82 shots from multiple rocket launchers for 8 1/2 hours in response to military drills between South Korea and the U.S. near the border.

"The successive artillery firings into the eastern maritime buffer zone are a clear violation of the Sept. 19 military accord, and we strongly urge the North to immediately halt them," the JCS said.

On Monday, the North fired some 130 artillery shells into eastern and western buffer zones.