MOSCOW, June 4 (RIA Novosti) - South Korea accused North Korea on Thursday of violating the western sea border between the countries, Seoul's Yonhap news agency reported.

A North Korean patrol boat crossed the Yellow Sea border at 14:47 local time (05:47 GMT) near the Northern Limit Line (NLL), where Pyongyang said last week it would be dangerous for South Korean vessels to operate, a South Korean official told the agency.

The agency said that the vessel turned back after a verbal warning from a South Korean warship.

The Northern Limit Line is a disputed maritime demarcation line in the Yellow Sea between North Korea and South Korea.

The line was unilaterally set by the U.S.-led UN military forces in August 1953 after the UN Military Command and North Korea failed to reach an agreement. It is not officially recognized by North Korea and is not included in the Armistice Agreement of 1953 between the two states.

The area saw two naval battles between the countries in 1999 and 2002.