A push alert that warned of an incoming ballistic missile to Hawaii and sent residents into a full-blown panic Saturday was a mistake, state emergency officials said.

The emergency alert, which was sent to cellphones, said in all caps, "Ballistic missile threat inbound to Hawaii. Seek immediate shelter. This is not a drill."

Hawaii Emergency Management Agency spokesperson Richard Repoza said it was a false alarm and the agency is trying to determine what happened.

Hawaiian Congresswoman Tulsi Gabbard tweeted about it, warning it was a false alarm.

Hawaii Sen. Brian Schatz said the false alarm was "totally inexcusable." 

Schatz went on his Twitter account after emergency management officials confirmed the push alert about an incoming missile Saturday was a mistake, calling for accountability and an alert process that is foolproof. 

He also said the event was the result of human error, but he did not explain what he meant.

The alert caused panic on the island and across social media.

Many people were still in bed when the alarm was triggered, including Canadian Elain Evans, a Vancouver resident who is staying with friends in a home north of Honolulu, on Oahu. 

Canadians in Hawaii tell their stories

She said she and her family gathered essentials and went to hide in a corner of the basement where they'd seen the dog take refuge during New Years Eve fireworks.

"We figured the dog would know best," Evans said. "We hid down there and tried to make phone calls ... the system was jammed with a weird message."

Evans and her family are scheduled to leave Hawaii for Vancouver Saturday evening.

"Two degrees have never felt so good as it will tomorrow morning when we get off that plane," she said.

Canadian Marissa Sciera, on her honeymoon in Maui, described loud alarms coming over the speakers in her hotel alerting her to the threat and advising people not to panic and to stay in their rooms. She and her husband were on the 12th floor of the hotel.

"Terrifying, terrifying. I was shaking and I was way calmer than my husband. It was horrifying," said the resident of Prince George, B.C. 

Jamie Malapit, owner of a Honolulu hair salon, texted his clients that he was cancelling their appointments and was closing his shop for the day. He said he was still in bed when the phone started going off "like crazy." He thought it was a tsunami warning at first.

"I woke up and saw missile warning and thought 'no way.' I thought `No, this is not happening today,"' Malapit said.

He was still "a little freaked out" and feeling paranoid even after hearing it was a false alarm.

"I went from panic to semi-panic and 'Are we sure?"' he said.