A South Korean naval ship fired warning shots at a North Korean patrol boat that crossed into contested waters west of the Korean Peninsula, according to a report on Tuesday.
The patrol boat retreated after the South Korean vessel opened fire, the Wall Street Journal reported, citing Seoul’s military.
The South Koreans then seized a second ship with seven North Koreans on board, all but one of whom were wearing military uniforms.
The encounter occurred near the western sea boundary known at the Northern Limit Line, an area that has seen a number of clashes over the years.
The South Korean military said the North Koreans had claimed under questioning that they were not intending to defect and their ship had crossed the Northern Limit Line by accident, according to the Journal.
The boundary was established following the 1953 armistice that halted hostilities in the Korean War. Pyongyang has objected to the position of the line in the past, saying it is too far north.
Seoul’s policy upon apprehending North Korean boats that drift south of the maritime border is to return the occupants to Pyongyang’s territory unless they express a wish to defect.
Tuesday’s incident happened on the eve of South Korea’s presidential election.