SEOUL, South Korea – North Korea fired artillery rounds toward its disputed sea border with South Korea on Wednesday, prompting a barrage of warning shots from the South's military and raising tensions on the divided peninsula.

No casualties or damage were reported, and analysts said the volley — which the North announced was part of a military drill — was likely a move by Pyongyang to highlight the need for a peace treaty to formally end the Korean War.
North Korea fired about 30 artillery rounds into the sea from its western coast and the South immediately responded with 100 shots from a marine base on an island near the sea border, an officer at the Joint Chiefs of Staff in Seoul said. The North said it would continue to fire rounds.
He said the North's artillery fire landed in its own waters while the South fired into the air. The officer spoke on condition of anonymity because of department policy.
The western sea border — drawn by the American-led U.N. Command at the close of the 1950-53 Korean War — is a constant source of tension between the two Koreas, with the North insisting the line be moved farther south.
Navy ships of the two Koreas fought a brief gunbattle in November that left one North Korean sailor dead and three others wounded. They engaged in similar bloody skirmishes in 1999 and 2002.
The North has sent a series of mixed signals to the South recently, combining offers of dialogue on economic cooperation with military threats, including one this month to destroy South Korea's presidential palace. South Korean Defense Minister Kim Tae-young, meanwhile, angered Pyongyang by saying Seoul's military should launch a pre-emptive strike if there was a clear indication the North was preparing a nuclear attack.
South Korea's Yonhap news agency said it was the first time that North Korea has fired artillery toward the sea border. The Joint Chiefs of Staff officer said the North Korean artillery shells were believed to have fallen into the no-sail zones about 1.75 miles (3 kilometers) north of the maritime border.