North and South Korea fired artillery shells into each other’s waters on Monday, forcing people on five South Korean islands on the frontline to evacuate their homes, the media reported.

South Korea said it fired shells into North Korean waters in response to live fire drills carried out by Pyongyang, Sky News reported, adding that North Korea fired more than 500 rounds during a three—hour drill.

“If the North takes issue with our legitimate returning of fire and uses it to make yet another provocation towards our sea and islands, we will make a resolute retaliation,” Kim Min—seok, a South Korea defence ministry spokesperson was quoted as saying.

He said South Korea responded by firing 300 shells into North Korean waters.

According to The Independent, North Korea on Monday announced that it would conduct live—fire drills in seven areas north of the Yellow Sea boundary between the nations.

The disputed western sea boundary has been the scene of several bloody naval skirmishes between the nations in recent years, including the 2010 artillery attack on Yeonpyeong by North Korea.

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