North Korea has test-fired a ballistic missile from a submarine but it failed in its initial flight stage, South Korea's military says.
It says the missile was launched in waters east of the Korean peninsula - the latest in a recent series of tests.
It comes less than three months after a previous attempt to launch a missile from a submarine failed.
North Korea, believed to be developing nuclear weapons, is banned by the UN from any use of ballistic missiles.
'Anti-missile system'
"The SLBM (submarine-launched ballistic missile) was ejected from the submarine normally, but is estimated the initial flight was unsuccessful," the South Korean military said in a statement.
"Our military strongly denounces such provocative acts by North Korea," it added.
The missile had been launched at about 11:30 local time (02:30 GMT) off North Korea's port of Sinpo.
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The US and South Korea on Friday agreed to deploy a missile defence system to counter threats from Pyongyang.
It remains unclear exactly where the Terminal High Altitude Area Defense (THAAD) anti-missile system will be sited and who will have final control.