The administrator of Hawaii's Emergency Management Agency has resigned and an officer with a track record of "poor performance" has been fired after triggering mass panic with a false alert of a ballistic missile headed for the Pacific islands, officials said Tuesday.

The Pacific archipelago, already on edge over the threat posed by North Korea, was terrorized by the erroneous alert, which was sent out by phone to residents and tourists and remained uncorrected for nearly 40 minutes.

Another employee of the state agency, which is responsible for notifying the public of threats to their safety, has been suspended, Major General Joe Logan, the state adjutant general, told reporters in Hawaii.

HEMA administrator Vern Miyagi resigned on Tuesday to take responsibility for the January 13 incident, Logan said, and the emergency warning officer who sent out the alert of an imminent ballistic missile attack was fired on Friday.

A state investigative report released on Tuesday said that the fired employee had been a "source of concern" for 10 years because of his "poor performance."

"He is unable to comprehend the situation at hand and has confused real life events and drills on at least two separate occasions," the report said.

In a separate report, the Federal Communications Commission (FCC) said the officer claimed he believed the threat was real and had not heard a phrase stating that it was an exercise.

At the same time, the report said, the sentence "This is not a drill" was included in the recorded message which prompted the officer to issue the alert.

Mobile phones across the Pacific islands received the emergency alert around 8:07 am and it was also transmitted by television and radio stations.

"In the minutes that followed, panic-stricken citizens called their families to say what they believed were their last words, and some even resorted to jumping into manholes to find shelter," FCC chairman Ajit Pai said in a statement accompanying the report.

The erroneous message came amid tensions with North Korea, which has tested rockets powerful enough to reach the United States, though it is unclear whether they are yet able to deliver nuclear payloads.