Tensions rise between Koreas in the Yellow Sea

North Korea fired into disputed waters near a South Korean warship Thursday in the latest sign of tension rising between the bitter rivals.

North Korea fired artillery toward a South Korean navy ship engaged in a routine patrol mission near the countries' disputed maritime boundary in the Yellow Sea. The South Korean ship was not hit, and it fired back at the North Korean vessel in response.

Residents of the Yeonpyeong island, which lies just south of the disputed sea border, were evacuated to bomb shelters. Shelling by North Korean artillery killed four people on the island in 2010.

Both Koreas regularly conduct artillery drills in the disputed waters.

Earlier on Thursday, North Korea had issued a threat to "blow up" any South Korean warships, in an angry response to an incident earlier in the week when the South fired warning shots at the North's patrol boats that breached the line.

The North accused the South of "a grave provocation" at the time and said its vessels were merely trying to contain Chinese fishing boats that were in the area illegally.

Also on Thursday, the South's Defense Ministry spokesman Kim Min-seok said North Korea had no business interfering in operations of South Korean naval vessels south of the Northern Limit Line.

North Korea has in recent weeks conducted a string of artillery drills and missile tests and has unleashed a torrent of racist and sexist rhetoric at the leaders of the United States and South Korea.

North Korean military ships and fishing boats have routinely intruded into South Korean-controlled waters that the North doesn't recognize. The Yellow Sea boundary was unilaterally drawn by the U.S.-led U.N. Command at the end of the 1950-53 Korean War.

Al Jazeera and wire services