North Korea warned it would open fire at any South Korean warships that trespass the maritime border following an incident involving North Korean patrol and fishing vessels, South Korean media report.

North Korea warned it would open fire at any South Korean warships that trespass the maritime border following an incident involving North Korean patrol and fishing vessels, South Korean media report.

On Friday, the South Korean Navy fired warning shots at North Korea’s fishing boat and patrol boat as they trespassed across the maritime border in the Yellow Sea (Northern Limit Line).

"From now on, we will open direct fire on any warship of the South Korean puppet forces without warning, if it intrudes into the extension of the Military Demarcation Line of our side even 0.001 mm in the hotspot of the west sea," the General Staff of the North Korean Army said in a statement, as quoted by The Korea Herald on Saturday.

According to the South Korean military, the North Korean vessels returned to the northern side immediately after the warning shots were fired.

Earlier this week, South Korea's Defense Ministry rejected military talks proposed by North Korea on Saturday in an effort to ease tensions on the Korean peninsula.

Pyongyang’s January hydrogen bomb test, as well as the launch, a month later, of a long-range rocket to allegedly place a satellite into orbit, in defiance of UN Security Council (UNSC) resolutions, led to a spike in tensions with Seoul and more sanctions having been imposed on North Korea by the UNSC and the United States.

South and North Korea are still formally at war, as no peace treaty was ever signed after the Korean War of 1950-1953.