Tensions escalated on the Korean peninsula today as the two Koreas exchanged fire for the fourth time in recent years near the western maritime border.
North Korea fired artillery shells at Yeonpyeong Island, some landing in sea but some landing on the island's residential area, said Col. Lee Bung-Woo, a spokesman for South Korea's Joint Chiefs of Staff.
The South responded with its own artillery fire.
South Korean media is reporting that 60 to 70 houses in the fishing village and areas in the mountains are on fire, engulfed in thick smoke.
Authorities said two South Korean soldiers were killed and 16 others were injured.
North Korea targeted the most populated area of the Yeonpyeong Island, bombarding village halls and telecommunications facilities.
At least three civilians have been hurt.
According to Lee, South Korean naval forces were conducting a routine drill in the waters near the island earlier in the morning.
"North Korea has sent a letter of protest over the drill," said Kim Hee-jung, spokesperson for the South's President Lee Myung-bak. "We're examining a possible link between the protest and the artillery attack." Reports also say North Korea repeatedly sent warnings to stop the exercises before firing the artilleries.
The South has upgraded the military's posture to its highest non-wartime alert, the defense ministry said. The Air Force has deployed fighter jets to the island and the government has ordered all residents in nearby west sea islands to evacuate.
A statement from the press office warned of retaliation.
"The firing of artillery by North Korea against Yeonpyeongdo constitutes an indisputable armed provocation against the Republic of Korea. Making matters worse, it even indiscriminately fired against civilians. Such actions will never be tolerated," it said. "The South Korean military will retaliate against any additional acts of provocation in a resolute manner."
U.N. Secretary General Ban Ki Moon called the attack one of "gravest incidents since the end of the Korean War" and said he "is deeply concerned by the escalation of tension on the Korean peninsula."
The White House also condemned the attack.
"The president is outraged by this action," deputy press secretary Bill Burton told reporters today. "We stand shoulder to shoulder with South Korea. ... North Korea has a pattern of doing things that are provocative. This is a part of that pattern."
President Obama, who was headed to Indiana, was not expected to speak on the subject there. Obama is expected to call South Korean President Lee today, and other world leaders, to discuss what actions to take.
The president's national security team met this afternoon to discuss the issue.
There were no U.S. forces involved in the annual South Korean training exercises, according to Pentagon spokesman Col. Dave Lapan. In years past, U.S. marines have participated in the exercise, but a scheduling conflict prevented their participation this year. Planning is still underway for a joint U.S.-South Korean exercise in the Yellow Sea, but the timing hasn't been announced.
Defense Secretary Gates called his South Korean counterpart today and reiterated the U.S. stance against "this act of aggression."