Meanwhile, South Korea struggled with the domestic political fallout from Tuesdayâ€™s deadly attack, which exposed the weakness of South Korean defenses and brought public criticism of President Lee Myung-bak for failing to retaliate more forcefully. On Friday, he appointed a new defense minister, whose predecessor resigned on Thursday for failing to keep forces at ready in an area that has seen repeated military clashes with North Korea.
North Koreaâ€™s state-run news agency lashed out at South Korean and American plans to hold a joint training exercise on Sunday in Yellow Sea waters near the island.
The exercises are to include the American aircraft carrier George Washington. Using its characteristically bellicose language, the Korean Central News Agency said that the Northâ€™s army was â€œgetting ready to give a shower of dreadful fire and blow up the bulwark of the enemies.â€
â€œThe situation on the Korean Peninsula is inching closer to the brink of war due to the reckless plan of those trigger-happy elements to stage war exercises targeted againstâ€ the North, the dispatch warned.
The arrival of the George Washington is intended as a warning to the North and a show of support for its ally, South Korea, following the Tuesday attack, the first by North Korea to strike civilians since the 1950-53 Korean War.
On Friday morning, the United States made another show of solidarity when the commander of American forces in South Korea, Gen. Walter L. Sharp, visited Yeonpyeong Island to survey the damage from the hour-long bombardment, which killed four South Koreans â€” two civilians and two marines.
But North Korea remained defiant, firing off artillery rounds right after the generalâ€™s visit. The rounds did not fall in South Korean territory but rattled nerves on the island nonetheless. A spokesman for the South Korean Defense Ministry, Kwon Ki-hyeon, said the shots appeared to stay within North Korean territory, suggesting they were part of a drill â€” or perhaps an effort to spook the South Korean garrison on the small island, which sits within sight of the North Korean mainland.
News flashes of the artillery sounds set off a brief wave of alarm in Seoul, where the Tuesday attack has stirred anxiety and outrage because it harmed civilians. Residents gathered in front of television screens or paused in their tracks to check cellphone screens for updates.
The events this week have raised concerns in Seoul that the North may respond violently during Sundayâ€™s naval exercises. Some media reports cited parallels between the K.C.N.A. report Friday and a warning issued by North Korea hours before Tuesdayâ€™s artillery barrage, which the North said was in response to a South Korean military maneuver held near the island earlier that day.
While reading the reclusive Northâ€™s intentions can be a challenge, experts said the Friday report was more vaguely worded, suggesting that it was intended as a broad warning to the United States and South Korea not to stray too closely to North Korean territory.
â€œIt is a message that North Korea will not yield if it believes the joint military training infringes on its sovereignty,â€ said Kim Keun-shik, a professor of international relations at Kyungnam University.
To thwart another North Korean attack, the South Korean president, Mr. Lee has ordered reinforcements to the 4,000 troops now on Yeonpyeong and four nearby islands as well as more heavy weapons. But his government has come under intense domestic criticism for what has been depicted as an inadequate retaliation for Tuesdayâ€™s attack, which South Korean troops on the island responded to with a smaller artillery counterattack.
Mr. Lee appointed Kim Kwan-jin, a former chairman of South Koreaâ€™s joint chiefs of staff as defense minister. Earlier on Friday, South Korean officials had named another appointee for the spot, but then withdrew the name when he apparently failed to pass an internal vetting process.
South Koreans have begun to get their first look at the damage to Yeonpyeongâ€™s small fishing town from reports by South Korean journalists describing a scene of devastation with dozens of homes burned out or flattened by the hour-long attack.
Television footage showed streets in the islandâ€™s main fishing port deserted by all but stray dogs after most civilians had evacuated the island. The islandâ€™s garrison of marines remained on high alert, with South Korean officials saying they were on the lookout for a reaction from North Korea to Sundayâ€™s military exercise.
While the island bristles with artillery batteries and machine gun nests, South Korean officials said its forces were unable to fully respond to Tuesdayâ€™s attack because they have been trained and equipped to thwart a North Korean amphibious assault, not fight off a prolonged artillery bombardment.
While the garrison did shoot back with 155-millimeter cannons, officials in the Blue House, South Koreaâ€™s version of the White House, said plans are afoot to reinforce the garrison with other types of heavy weaponry.
In his visit to the island, General Sharp expressed sympathy for those killed and said many lives appeared to be saved by the quick response of local civil defense officials, who herded townspeople into bomb shelters. He also called on North Korean Peopleâ€™s Army to refrain from further attacks and to hold talks on the incident.