SEOUL - South Korea's Navy drove off a boat that crossed a tense maritime border from the north, the Joint Chiefs of Staff (JCS) in Seoul said Wednesday.

The boat from the Democratic People's Republic of Korea, believed to be a patrol ship, trespassed into South Korean waters at 9:23 pm on Tuesday but soon drove away after South Korea fired warning shots, according to JCS officials.

The tense Yellow Sea border, called the Northern Limit Line, was drawn at the end of the 1950-53 Korean War by the US-led United Nations Command.

South Korea and the DPRK have had several naval skirmishes near the border, which Pyongyang never officially acknowledged.