The bombardment of Yeonpyeong was an artillery engagement between the North Korean military and South Korean forces stationed on Yeonpyeong Island on 23 November 2010. Following a South Korean artillery exercise in disputed waters near the island, North Korean forces fired around 170 artillery shells and rockets at Yeonpyeong Island, hitting both military and civilian targets.The shelling caused widespread damage on the island, killing four South Koreans and injuring 19. South Korea retaliated by shelling North Korean gun positions. The North Koreans subsequently stated that they had responded to South Korean shells being fired into North Korean territorial waters.The incident caused an escalation of tension on the Korean Peninsula and prompted widespread international condemnation of the North's actions. The United Nations declared it to be one of the most serious incidents since the end of the Korean War, and by 18 December, former US ambassador to UN Bill Richardson said tensions had escalated to become "the most serious crisis on the Korean peninsula since the 1953 armistice, which ended the Korean War".