North Korea launched several unidentified projectiles into the sea on Saturday morning, South Korea's military reported.

The US Joint Chiefs of Staff were still analyzing an "unidentified projectile" that was launched from the eastern province of Gangwon into waters off of the coast. The objects flew about 250 kilometers (155 miles).

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The US military detected three short-range ballistic missiles. It said the first and third missile appeared to have failed in flight, while the second blew up almost immediately after launch. 

The missiles did not pose a threat to Guam or North America, according to the US military. Japanese broadcaster NHK said the projectiles did not appear to pose a threat to Japan's safety.

South Korea's Yonhap news agency reported that it could have been a ballistic missile, without citing a source.

According to Yonhap, the launch was immediately reported to President Moon Jae-in.

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The launch came a day after an important national holiday in North Korea, the Day of Songun.

North Korea successfully tested two intercontinental ballistic missiles in July. Analysts said the tests showed that its missiles had the potential to reach the US mainland.

South Korea and the US are holding annual defensive drills, which North Korea routinely describes as preparation for invasion.

aw/kl (Reuters, dpa)