North Korea fired multiple unidentified cruise missiles on Tuesday into the sea off its west coast, South Korea's military said, the third time Pyongyang has tested cruise missiles in less than a week.
The missiles were launched at around 7:00 am (2200 GMT on Monday), Joint Chiefs of Staff said in a statement.
South Korean and US intelligence authorities were closely monitoring the situation and analysing the details of the launch, it said.
The launch comes amid a rise in tension on the Korean peninsula and follows a barrage of cruise missiles fired by Pyongyang off its east coast on Sunday.
Sunday's launch was a test of the new submarine-launched cruise missiles (SLCM) dubbed "Pulhwasal-3-31" and leader Kim Jong Un supervised the test, North Korean state media KCNA reported on Monday.
Last week's missiles were also Pulhwasal-3-31, KCNA said, adding that they were "strategic", which typically refers to nuclear-capable weapons.
South Korea's JCS said last week it believes the firing of "Pulhwasal-3-31" was to test upgrades of existing missiles' capabilities.

US military says it turned away blockade runner trying to reach Iranian port
Jubilant PSG supporters spill onto Paris streets, some clash with police
WHO chief urges safe burials in visit to heart of Ebola outbreak
Rescuers pull four from flooded cave in Laos
