There has been a clash between ships from the rival navies of North and South Korea, military officials in Seoul say.

首尔军事官员称，朝鲜、韩国双方海军军舰发生一起冲突事件。

A South Korean warship¹ fired a shot at a North Korean vessel² which crossed the demarcation line（分界线） off the two countries' western coast, officials said.

The North Korean ship returned fire, but the South reported no injuries.

The two navies have engaged in deadly exchanges twice along their western sea border in the past decade.

There has so far been no comment on the incident from North Korea.

The North Korean ship was seriously damaged, before it sailed back into its territorial³ waters, the South Korean officials said.

The South Korean ship, they added, suffered no damage.

Northern limit

In October, North Korea's navy accused South Korea of sending warships⁴ across their maritime⁵（海上的，海事的） border to stir（激起，搅合） tensions, and warned that further incursions（袭击，侵入） could spark retaliations.

The communist state's navy said that on one day alone, ships had crossed the boundary 10 times.

South Korea recognises the Northern Limit Line, drawn⁶ unilaterally（单方面的，单边的） by the US-led United Nations Command at the end of the 1950-53 Korean War, which has never been accepted by North Korea.

In 1999 a North Korean ship was sunk and several vessels⁷ from both sides were damaged during an exchange of fire.

In 2002 four South Korean sailors and an estimated 30 North Koreans were killed in a 20-minute battle.