North Korean soldiers stage an artillery firing exercise, in this photo carried by the North's Korean Central News Agency on Oct. 10. Yonhap

South Korea says North Korea has fired artillery shells near the rivals' sea border in its latest weapons test.

South Korea's Joint Chiefs of Staff says North Korea fired about 100 shells off its west coast and 150 rounds off its east coast on Tuesday night.

It says the shells fell inside maritime buffer zones the two Koreas established under a 2018 inter-Korean agreement on reducing tensions.

In recent weeks, North Korea has conducted a spate of missile and artillery launches in what some experts call an attempt to expand its weapons arsenal and boost its leverage in future negotiations with its rivals. (AP)