There has been an exchange of artillery fire between North and South Korea in the area of the two countries’ disputed sea border in the Yellow Sea.

North Korea initially fired into the sea in what it described as a routine artillery drill. The South Korean army then returned warning shots.

The firing came a day after North Korea had declared a ‘no sail zone’ in the disputed region. The south concluded this was a sign that Pyongyang was preparing to carry out new missile tests.

The two Koreas have been arguing over the location of their sea border since the Korean War in the early 1950s. In November there was an exchange of fire between North and South Korean naval vessels in the region.