Hours after North Korea's deadly artillery attacks Tuesday, South Korea's president said "enormous retaliation" is needed to stop Pyongyang's incitement, but international diplomats urgently appealed for restraint.
The incident -- in which two South Korean marines died -- is "the first direct artillery attack on South Korean territory since the Korean War ended in an armistice" in 1953, Yonhap reported.
In addition to the slain marines, 15 South Korean soldiers and three civilians were wounded when North Korea fired about 100 rounds of artillery at Yeonpyeong Island in the Yellow Sea, South Korean authorities said. Hundreds of island residents boarded boats and fled to safety, as the attack also set houses and forests on fire.
Some U.S. forces had been helping the South Koreans in a military training exercises, but were not in the shelled area.South Korea's military responded with more than 80 rounds of artillery and deployed fighter jets, defense officials said.
Firing between the two sides lasted for about an hour in the Yellow Sea, a longstanding flash point between the two Koreas. In March, a South Korean warship, the Cheonan, was sunk in the area with the loss of 46 lives in a suspected North Korean torpedo attack.
The United States has about 28,500 troops deployed in South Korea. A U.S. defense official said more than 50 U.S. Navy vessels are in the area, including a carrier strike group led by the USS George Washington.
U.S. President Barack Obama defended South Korea.