North and South Korea say they have exchanged warning shots along their disputed western sea boundary.South Korea's military says its Navy fired warning shots to repel a North Korean merchant ship that it says violated the sea boundary early on Monday.North Korea's military said it responded by firing 10 rounds of artillery shells as a warning to South Korea.

North and South Korea say they have exchanged warning shots along their disputed western sea boundary.South Korea's military says its Navy fired warning shots to repel a North Korean merchant ship that it says violated the sea boundary early on Monday.North Korea's military said it responded by firing 10 rounds of artillery shells as a warning to South Korea.