North Korea fired several short-range missiles into the sea off its east coast early on Saturday, South Korea and the U.S. military said, as the two allies conducted annual joint military drills that the North denounces as preparation for war. "The second missile launch... appears to have blown up nearly immediately", said the spokesman, Commander Dave Benham, adding that the launches happened over a span of 30 minutes.
The North fired three ballistic missiles in a half-hour timespan, U.S. Pacific Command said.
Saturday's launch comes during an annual joint military exercise between the United States and South Korea that the North condemns as an invasion rehearsal, and weeks after Pyongyang threatened to lob missiles toward Guam.
They come during a joint military exercise between the US and South Korea.
Later on Saturday, the South Korean Presidential Blue House said the North may have fired an upgraded 300-mm calibre multiple rocket launcher but the military was still analysing the precise details of the projectiles.
South Korea's Yonhap news agency and Japan's Kyodo news service said it may have been a ballistic missile, without citing a source.
"We confirmed there was no direct impact on our country's security".
A day before the exercises began Monday, Pyongyang warned the United States was risking an "uncontrollable phase of a nuclear war".
North Korea Fires 3 Short-Range Ballistic Missiles, US Says
The "Ulchi Freedom Guardian" war games are a largely computer-simulated exercise that runs for two weeks in the South. South Korea has also been testing new missiles of its own, including the 800-kilometer (497 mile)-range Hyunmoo-2.
While Texas deals with the aftermath of Hurricane Harvey and the media has worked itself into a frenzy over the pardoning of former Maricopa County, Arizona, Sheriff Joe Arpaio, North Korea has found another way to rattle the cage during tense times.
North Korean state-run media said the country's military could strike the U.S. at any time and that neither Guam, Hawaii nor the USA mainland could avoid the "merciless strike".
North Korea has still issued angry statements about the exercises, saying most recently that they were evidence that the United States planned to invade the country.
Earlier this month, Washington's top diplomat suggested a diplomatic opening might be close after North Korea reacted to a new round of United Nations sanctions with what he termed "some level of restraint".
"Having said that, we are going to continue our peaceful pressure campaign as I have described it", Tillerson said, "working with allies, working with China as well, to see if we can bring the regime in Pyongyang to the negotiating table, begin a dialogue on a different future for the Korean peninsula and for North Korea".
The launches puzzled analysts because North Korea does not typically have problems with tried and tested short-range missiles like Scuds.
Earlier this month Trump had warned that North Korea would be met with "fire and fury", if it continued with its threats.
Kim has been aggressively pursuing more advanced missile technology, and North Korea has now conducted 17 launches so far this year. In July, it launched an intercontinental ballistic missile, which North Korea claims could reach "anywhere in the world".