North Korea fired over 200 artillery rounds into the maritime buffer zone near South Korea's Yeonpyeong and Baengnyeong islands on Friday morning. The shells landed north of the Northern Limit Line, a disputed border from the Korean War era. South Korea condemned the act as "provocative" and threatened countermeasures. It conducted its own artillery drills in the area later on Friday. Yeonpyeong residents were evacuated to shelters during the South Korean drills as a precaution.