South Korean marines walk past at houses destroyed by North Korean shelling during a rally today on the Yeonpyeong Island. South Korean fighter jets dropped bombs and tanks fired artillery today as the military staged its largest air and ground firing drills of the year in a show of force a month after North Korea's deadly shelling of a front-line island.

POCHEON, South Korea — North Korea threatened today to launch a sacred nuclear war against South Korea if it attacks, as Seoul staged military exercises that have raised already high tensions on the peninsula.

The remarks seemed aimed at revving patriotic spirit on the eve of the 19th anniversary of leader Kim Jong Il’s appointment as the supreme military commander.

Defense chief Kim Yong Chun said North Korea is “fully prepared to launch a sacred war” — and would use its nuclear capabilities — if attacked and warned the South against intruding even the smallest amount on its territory, according to the official Korean Central News Agency.

North Korea’s anger has been piqued this week by South Korea’s staging of live-fire drills on Yeonpyeong Island, which was shelled by the North’s artillery on Nov. 23. Four South Koreans were killed.

North Korea has said it shelled the island because South Korea fired artillery into its territorial waters first. South Korea has countered that it fired artillery away from North Korea as part of routine drills.

Earlier today, South Korea conducted its largest air-and-ground firing drills near the tense land border in a show of force against North Korea. The North’s state media has called the drills “provocative” and “offensive.”

The two Koreas are still technically at war because their 1950-53 Korean War ended with an armistice, not a peace treaty.