Distant artillery fire was heard early on Wednesday near the tense Yellow Sea border between North and South Korea, Yonhap reported.
The agency said North Korea was conducting a regular drill.
"No shells have landed south of the border or on Yeonpyeong Island," Yonhap quoted an unnamed military source as saying.
Tensions escalated in the region in mid-November when North Korea launched artillery fire at South Korea's Yeonpyeong island, killing four people and provoking a retaliatory attack from the South.
MOSCOW, December 8 (RIA Novosti)
