Lawmakers from South Korea's ruling and opposition parties had demanded that Defense Minister Kim Tae-young step down, amid growing public criticism that the military mishandled Tuesday's clashes on Yeonpyeong Island. Two South Korean marines died as well as two civilians, in a surprise bombardment by the communist North.
Kim toured the island's devastation today and then afterward handed in his resignation. A replacement will be named on Friday, Yonhap news agency reported.
Meanwhile, as civilians continue to flee the island at the heart of the peninsula's latest showdown, South Korean troops are marching the opposite way, beefing up defenses ahead of another possible attack. South Korean President Lee Myung-bak huddled for an emergency meeting in Seoul, telling reporters that another strike by the North "could come at any time."
"We should not let our guard down in preparation for another possible North Korean provocation," presidential spokesman Hong Sang-pyo quoted him as saying, according to The Associated Press. Troop levels will be boosted on Yeonpyeong and four other islands in the same area, reversing a 2006 decision that called for a military drawdown, Hong said.
Some South Koreans have blamed their government for not acting more forcefully to prevent attacks like Tuesday's artillery barrage. Yeonpyeong Island, about twice the size of New York's Central Park, lies near the invisible, disputed sea boundary between North and South Korea, and while naval skirmishes in the area are somewhat frequent, the island's civilian population has never come under bombardment before.
South Korean Lee Cheon-gu told VOA News he believes the government in Seoul is partly to blame for the latest attack, after being too lenient with North Korea. After the sinking of the warship Cheonan in March, the South Korean government didn't act strongly enough to prevent more attacks, he said.
Yeonpyeong lies in the same area of the Yellow Sea where the Cheonan sank, killing 26 South Korean sailors in a suspected attack blamed on a Northern torpedo. Pyongyang denies that.
While South Korea bolsters its defenses, Pyongyang is also warning of retaliation for any "reckless military provocations." A military statement carried by state media said the North would launch "strong physical retaliations without hesitation if South Korean warmongers carry out reckless military provocations," The Guardian reported.
"We have taken note of relevant reports and express concern," ministry spokesman Hong Lei told reporters in Beijing, according to Agence France-Presse. "We oppose any act that undermines peace and stability on the (Korean) peninsula."
Hong was responding to questions about joint U.S.-South Korean military exercises, which are slated to include the mammoth USS George Washington, one of the largest aircraft carriers in the world, scheduled to kick off Sunday.
Earlier, the Foreign Ministry issued a statement quoting Premier Wen Jiabao as saying his country was against "any provocative military acts" on the Korean peninsula and urged all sides to "show restraint." It's unclear whether he was talking about Tuesday's artillery exchange on Yeonpyeong Island, or the upcoming U.S. military drills.
Either way, it's not the strong response from China that Washington and Seoul hoped for. Both countries are pushing China to use its influence with Pyongyang, but those efforts come at an already tense time for Beijing's stance on North Korea, because of its disputed nuclear program. China wants to restart six-nation talks aimed at Pyongyang's disarmament, but Obama's North Korea envoy, Stephen Bosworth, ruled out the talks' resumption this week amid the discovery of a previously unknown nuclear laboratory.