South Korean warships staged a live-fire drill Tuesday in a show of strength towards North Korea despite its threats to retaliate, the defence ministry said.

The drill took place in the Yellow Sea to test readiness against infiltrations by North Korean warships and submarines.

"Today's drill shows our strong will not to tolerate further provocations by North Korea," a ministry spokesman told AFP, referring to the deadly bombardment of a South Korean border island last year.

The drill was part of a broader exercise involving about 20 destroyers, frigates and patrol boats as well as helicopters and anti-submarine surveillance aircraft, he said.

South Korea last week held a major land, sea and air exercise near the disputed Yellow Sea border to mark the anniversary of the island attack on November 23, 2010.

Those manoeuvres triggered an angry reaction from North Korea, which threatened to turn the South's presidential palace into a "sea of fire" in response to any provocation.

Last year's shelling killed two Marines and two civilians and damaged scores of buildings. It was the first attack on a civilian-populated area since the 1950-1953 war and caused outrage in the South.

Tensions have eased slightly in recent months but the South vows to hit back hard with artillery and air power for any fresh attack.