The action follows North Korea firing more than 200 artillery rounds on Friday in the same region, as tension continues to escalate between the two Koreas.

The artillery was fired around the northwest of Yeonpyeong Island between 1600-1700 Saturday KST (0700-0800 GMT), South Korea's Joint Chiefs of Staff said in a statement.

The Joint Chiefs of Staff "strongly urged" North Korea to stop acts that threaten peace on the Korean Peninsula and escalate tensions.

(Reporting by Joyce Lee; Editing by Jan Harvey)