SEOUL - NORTH Korea has violated the disputed sea border with South Korea 21 times this year, according to a Defence Ministry report released on Wednesday.

Seven of the violations were by North Korean patrol boats and the others by fishing vessels and other smaller civilian boats, the ministry said in a report to ruling party lawmaker Chin Young.

The report, provided by Chin's office, said the North's boats turned back following radio warnings from the South.

It did not specify the dates of the incursions.

North Korea does not recognise the sea boundary off the divided peninsula's west coast. The communist nation claims that the United Nations unilaterally drew the line at the end of the 1950-53 Korean War, and that it should be redrawn further south.

The dispute, which led to two bloody naval skirmishes in 1999 and in 2002, has long been a deal breaker in military talks between the two sides.

Last year, North Korea boats violated the sea border 28 times, the report said.

The Korean War ended in a truce, not a peace treaty, leaving the peninsula still technically at war. -- AP