North Korean soldiers have boasted on state television they bombarded a front-line South Korean island with artillery last month as immediate retaliation after the South fired first.
The two Koreas have ramped up their rhetoric since the November 23 attack killed four South Koreans on Yeonpyeong Island near their tense western sea border. North Korea has said it fired after South Korean shells landed in its waters, while the South has said its routine firing drill aimed away from the sea frontier and should not have provoked an attack.
North Korea's war of words intensified around Saturday's 19th anniversary of leader Kim Jong Il's appointment as the North's supreme military commander. Mr Kim's military chief threatened last week to launch a "sacred" nuclear war against the South.
On Friday, North Korean soldiers appeared on a state TV programme marking Mr Kim's appointment anniversary and bragged of participating in the artillery barrage.
"Our eyes were full of fire right after we saw the enemy's shells being fired into our sacred waters," soldier Kim Moon Chol said, clinching his fists and standing shoulder-to-shoulder with three uniformed colleagues. Their ranks were unknown. "At the order of 'fire,' we poured our merciless thunderbolt of fire at the enemy," he said in a loud, oratory-style speech.
A soldier whose uniform was full of military decorations expressed his loyalty to Kim Jong Il.
"Facing the enemy's provocation, we shouted, 'Let's dedicate our lives to fighting the enemy and giving them a merciless death for our dear leader and supreme military commander,'" Kim Kyong Su said.
Their speeches constantly drew applause from the audience - mostly uniformed soldiers who spoke separately and vowed to get tougher with South Korea. They all later sang a military song together.
South Korea has staged a series of military drills - including one on Yeonpyeong Island - in a show of force against the North. The South's President Lee Myung-bak, during a visit to front-line troops, said that South Korea must make "unsparing" retaliation if it suffers another surprise attack.
South Korea plans new routine naval firing exercises starting on Monday but not on Yeonpyeong and other border islands, according to the country's defence ministry.