The US Federal Communications Commission said it was launching a full investigation into a false wireless emergency alert that a ballistic missile was headed for Hawaii, the chairman of the commission said.
The FCC is launching a full investigation into the false emergency alert that was sent to residents of Hawaii, FCC chairman Ajit Pai said in a Twitter post.
The emergency alert that some mobile phone users received read: "BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL."
"The president has been briefed on the state of Hawaii's emergency management exercise. This was purely a state exercise," White House spokeswoman Lindsay Walters said.
The US military's Pacific Command said it "detected no ballistic missile threat to Hawaii" and that the message warning had been sent in error.
NO missile threat to Hawaii.— Hawaii EMA (@Hawaii_EMA) January 13, 2018
The incident occurred amid high international tensions over North Korea's development of a ballistic nuclear weapon.
North Korean President Kim Jong-un has threatened to unleash his country's growing missile weapon capability against the US territory of Guam or US states, prompting US President Donald Trump to threaten tough actions against Pyongyang.
Hawaii, a chain of islands in the Pacific Ocean, has a population of about 1.4 million people, according to the US Census Bureau, and is home to the US Pacific Command, the navy's Pacific fleet and other elements of the American military.
In November, Hawaii said it would resume monthly statewide testing of Cold War-era nuclear attack warning sirens for the first time in at least a quarter of a century, in preparation for a possible missile strike from North Korea, state officials said at the time.