Hawaii was plunged into panic on Saturday when an official alert warned people a ballistic missile was about to hit - only for it to turn out to be a false alarm. Residents in the American state, which has a population of almost 1.5 million, reportedly ran for cover when they spotted the message on their smartphones. "BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL," the emergency alert read. Children were seen sheltering in locker rooms while others were witnessed looking “terrified” and crying, according to a congressman for the state. However it was later discovered that a button had been pressed in “human error” during a change in shifts, wrongly issuing the warning. An information related to a false emergency alert is displayed in Oahu, Hawaii Credit: REUTERS The blunder caused further fury after it took 38 minutes to alert people via the same system that the original message was incorrect. “There is no missile threat or danger to the State or Hawaii. Repeat. False Alarm,” the second message read. Between the two messages other national bodies and politicians had confirmed it was a blunder and posted messages online announcing the fact. The incident was so serious that Donald Trump, the US president, was briefed about what had happened. White House spokeswoman Lindsay Walters said it "was purely a state exercise." HAWAII - THIS IS A FALSE ALARM. THERE IS NO INCOMING MISSILE TO HAWAII. I HAVE CONFIRMED WITH OFFICIALS THERE IS NO INCOMING MISSILE. pic.twitter.com/DxfTXIDOQs— Tulsi Gabbard (@TulsiGabbard) January 13, 2018 Hawaii officials apologised for the mistake and an investigation is now underway to work out exactly what went on. "I deeply apologise for the trouble and heartbreak that we caused today," said Vern Miyagi, administrator of Hawaii's Emergency Management Agency. "We've spent the last few months trying to get ahead of this whole threat, so that we could provide as much notification and preparation to the public. "We made a mistake," he told journalists. "We're going to take processes and study this so that this doesn't happen again. "The governor has directed that we hold off any more tests until we get this squared away." The blunder comes at a time of heightened tension between America and North Korea, with the latter testing ballistic missiles over increasingly long distances. Brian Schatz, the senator for Hawaii, said of the officials: "They blew it here. It was totally unacceptable ... they don't quite understand how bad this was.” He told CNN: “The fact that the state government knew it was a false alarm but took between 30 and 40 minutes to alert the public is just an abomination." AGAIN FALSE ALARM. What happened today is totally inexcusable. The whole state was terrified. There needs to be tough and quick accountability and a fixed process.— Brian Schatz (@brianschatz) January 13, 2018 Lauren McGowan, on holiday in Maui with family members and friends, was on her way to breakfast when her phone blared the alert. She and her family quickly returned to their hotel, where staff ushered them along with some 30 people to a basement cafeteria and distributed water and food. The alert and rush to shelter caused "confusion," McGowan said, particularly for the children in the group. "No one had any idea what was really going on," the 28-year-old from New York told AFP, explaining they had no cell service underground. "It was a bit jarring for sure," she said of the experience. But McGowan added, "I'm not going to let it ruin the rest of my vacation" and it's "definitely good to know that the system works."