North, South Korean boats 'exchange fire'

North and South Korean naval patrol boats have exchanged fire near the island of Yeonpyeong, officials from the South say.

North and South Korean naval patrol boats have briefly exchanged fire near their disputed maritime border, according to the South's defence ministry which said the North's vessel had violated the boundary.

The incident took place at 9.50am (1150 AEDT) on Tuesday near the South Korean border island of Yeonpyeong, when the North patrol boat crossed into the South's water, a ministry spokesman said.

"Our side fired back when the North Korean patrol boat opened fire," he said.

"There was no damage."