SEOUL, Oct 15 (AFP) - North Korea on Saturday warned that it would take "overwhelming military countermeasures" against what it called deliberate provocations by South Korea, as tensions remained high following the North's ballistic missile launches in recent weeks.

The warning by an unnamed spokesman of the North's Korean People's Army (KPA) came a day after it fired a short-range ballistic missile into the sea and hundreds of artillery rounds near the border with the South.

KPA frontline units conducted artillery firing on Friday to send a clear warning to "repeated provocation by the enemies in the front areas," the spokesman said in a statement carried by the North's official KCNA news agency.

"In the future, too, our army will never allow any provocation by the enemies escalating the military tension on the Korean Peninsula but take thorough and overwhelming military countermeasures," it said.

North Korea also flew warplanes close to the military border with the South on Friday, prompting the South to scramble fighter jets.

South Korea on Friday said its artillery fire was "regular, legitimate" exercise.