Please answer the following question: Extract the answer to the question from the following context. Question: Where was invaded? Context: By mid-1950, North Korean forces numbered between 150,000 and 200,000 troops, organized into 10 infantry divisions, one tank division, and one air force division, with 210 fighter planes and 280 tanks, who captured scheduled objectives and territory, among them Kaesong, Chuncheon, Uijeongbu, and Ongjin. Their forces included 274 T-34-85 tanks, 200 artillery pieces, 110 attack bombers, some 150 Yak fighter planes, 78 Yak trainers, and 35 reconnaissance aircraft. In addition to the invasion force, the North KPA had 114 fighters, 78 bombers, 105 T-34-85 tanks, and some 30,000 soldiers stationed in reserve in North Korea. Although each navy consisted of only several small warships, the North and South Korean navies fought in the war as sea-borne artillery for their in-country armies.
Answer:
Kaesong, Chuncheon, Uijeongbu, and Ongjin