South and North Korea exchange fire across sea borders in Yellow Sea

South Korea fired hundreds of artillery shells at North Korean waters in response to North Korea’s live-fire drills on Monday, Associated Press reports.

North Korea first fired 500 rounds of artillery shells for more than three hours after a last minute announcement that it would conduct military drills in areas north of the Koreas’ disputed maritime bounty. When 100 of the shells fell into the South Korean waters, Seoul responded by firing 300 rounds into the northern waters.

Although there were no shells fired at any land, military camps or naval and fishing boats, the fire exchange forced residents of five first-line islands to evacuate to a bomb shelter and closed down ferry services to the islands.

South Korean Defense Ministry spokesman Kim Min-seok told reporters that North Korea could have been testing South Korea’s security posture. The New York Times called Monday’s event “the most serious episode along that border since an artillery duel in 2010.”