North Korea on Saturday fired several unidentified short-range projectiles into the sea off its eastern coast, the South Korean Joint Chiefs of Staff said, a likely sign of Pyongyang’s growing frustration at stalled diplomatic talks with Washington meant to provide coveted sanctions relief in return for nuclear disarmament. The South initially reported a single missile was fired, but later issued a statement that said “several projectiles” had been launched and that they flew up to 200 kilometers (125 miles) before splashing into the sea toward the northeast. South Korea’s military has bolstered its surveillance in case there are additional weapons launches, and South Korean and US authorities are analyzing the details. If it’s confirmed that the North fired banned ballistic missiles, it will be the first such launch since the North’s November 2017 test of an intercontinental ballistic missile. That year saw a string of increasingly powerful weapons tests from the North and a belligerent response from President Donald Trump that had many in the region fearing war. The firing Saturday comes amid a diplomatic breakdown that has followed the failed summit earlier this year between Trump and North Korean leader Kim Jong Un over the North’s pursuit of nuclear bombs that can accurately target the US mainland. Experts believe that the North has viable shorter range nuclear armed missiles but still needs more tests to perfect its longer-range weapons. During the diplomacy that followed the North’s weapons tests of 2017, Kim Jong Un said that the North would not test nuclear devices or ICBMs. These short-range projectiles don’t appear to violate that self-imposed moratorium, and may instead be a way to register Kim’s displeasure with Washington and the state of talks meant to provide sanctions relief for disarmament without having the diplomacy collapse.