Pyongyang has test-fired a submarine-launched ballistic missile but the Yonhap news agency said the test failed. It quoted a senior South Korean government source as saying the launch was probably a misfire.
The Seoul-based news agency reported that a North Korean KN-11 missile was fired between 2.20 p.m. (0520 UTC) and 2.40 p.m. local time on Saturday.
The submarine-launched ballistic missile (SLBM) was discharged from a submerged barge in the Sea of Japan but there was no indication that the missile successful ejected from the vessel and took off, it said.
Quoting an unnamed South Korean government official, Yonhap reported that the rocket flew about 150 meters (490 feet) out of the water.
"There is no identification of a missile taking flight and only fragments of a safety cover were observed so it's highly likely that the launch was a misfire," the source was cited as saying.
North Korean officials have yet to reveal details of the test, but they did declare a no-sail zone off the country's eastern coast two weeks ago.
Pyongyang is still years away from developing submarine missile launch technology, the Reuters news agency reported.
If Saturday's test is confirmed, it would be the first missile test since a similar projectile was launched in May, which North Korean officials lauded as a success.
The incident caused international alarm about possible advances in the military capabilities of the isolated Communist state, which has also developed its own nuclear technology.
But some military experts say that photos released by Pyongyang in May were likely modified.
South Korea's defense ministry declined to confirm Saturday's report.
Under United Nations Security Council resolutions, North Korea is banned from any test using ballistic missile technology and has faced international sanctions.
Pyongyang also carried out three nuclear tests between 2006 and 2013.
North and South Korea remain technically at war after an armistice instead of a peace treaty in 1953.
mm/rc (AFP, dpa, Reuters)